Skip to main content

Medical specialties

Learn about the specialties doctors practise in Ontario

There are 47 distinct specialties comprised of more than 33,000 doctors who provide care to Ontarians. Read stories from leaders within each specialty about the services they provide to Ontarians.

Addiction medicine

Practising doctors: 173

Addiction medicine doctors provide prevention, evaluation, diagnosis and treatment for patients with substance use disorder. They also work to de-stigmatize addiction and they help family members who are affected by a loved one’s substance use. Doctors practising addiction medicine also provide support/treatment for non-substance related addictive disorders.

From Dr. Chris Cavacuiti, addiction medicine specialist and chair of OMA Section on Addiction Medicine: 

“Substance use disorder is an equal opportunity disease. It doesn’t care how old you are, your gender, your cultural background, or which neighbourhood you live in. About one out of 10 of us will meet the criteria for a substance use disorder over our lifetime – either alcohol or drugs. Just over 180 doctors in Ontario list ‘addiction medicine’ as their primary focus, but another 400 have addiction medicine as a secondary specialty. Most doctors who practice addiction medicine are family physicians. There are also quite a few psychiatrists and some emergency medicine physicians who do this work.

“Every day we see how devastating substance use disorder can be for our patients: multiple accidental overdoses and emergency room visits, losing everything including friends, family, job, and home, and even more health issues caused by diseases like HIV or Hepatitis C. One of the fastest-growing addictions today is opioid use disorder. This is a very stigmatized illness. Our patients tell us that they are looked down on by friends, family and even the medical community. After all, it’s their fault, isn’t it? But the science says that opioid disorder is a disease, not just a lifestyle choice, and should be looked at that way.

“Let’s compare opioid use disorder with another very prevalent disease: Type 2 diabetes. In Type 2 diabetes, the body doesn’t produce enough insulin to process all the extra glucose produced when we choose to eat too many sugary foods. In opioid use disorder, because the patient has been exposed to lots of artificial opioids, their body no longer responds to the natural levels of opioids we produce called endorphins.

“In the same way that Type 2 diabetics don’t produce enough insulin, the endorphins produced naturally by those with opioid use disorder simply aren’t enough for them. These patients go through painful withdrawal that prevents them from functioning normally. If you want some sense of what it is like to live with opioid use disorder, try this thought experiment: read the next few paragraphs while holding your breath. After a minute or so, your craving to breathe is likely as strong as an opioid user’s cravings for their drug. For most of us, it is almost impossible to think and function normally while in the throes of a primal urge like that. Now think about what it must be like to live day-in and day-out with a craving that strong. No wonder relapse rates with medication assistance are 95 per cent or higher.

“When you look at addiction and compare it to other chronic diseases with genetic and lifestyle components and the percentage of illness actually under the patient’s control, it turns out there are also more similarities than differences. Our patients don’t always make great choices, but the same can be said about high blood pressure patients who smoke or have a lot of salt in their diet or diabetes patients who eat cake. However, illnesses such as hypertension and diabetes are seen as medical issues while addiction is far too often seen as a moral failing.

“Most people with a substance use disorder are no longer chasing a high – they just want to feel normal again and to stop suffering from terrible withdrawal symptoms if they stop taking the drug. The good news is that huge advances in treatment mean much better outcomes for patients than were ever possible before.

“The best way to treat opioid addiction is to offer medications within a structured program. This approach is called opioid agonist treatment. The most common medications we use in this approach are methadone and suboxone. We’re essentially taking our patients off the short-acting, high potency drugs they have problems with and on to lower potency, longer-acting medications. This way patients get an ongoing steady amount of opioids. The medications they are prescribed have enough potency that the patients don’t experience withdrawal but are low enough that the patients don’t get high. Taking these medications can change the outlook for a patient virtually overnight – they’re that effective!

“I can totally understand why people say, ‘You’re giving addicts more drugs – that can’t be right.’ However, someone can be in recovery and still take suboxone or methadone. You have to look at it not as ‘drugs’ but as medicine. We’re treating their addiction, not contributing to their addiction.

“Are medications the magic bullet to cure addiction? No. Counselling is very important as a part of treatment, and many addiction medicine physicians work in a multi-disciplinary team environment. But what makes addiction medicine physicians unique is our ability to also provide this very important medication component. It’s not a band-aid solution but an important tool. Again, it’s very similar to the treatment of other diseases. There are people with diabetes who can make lifestyle changes and reduce the need for medication over time. The same is true for patients on opioid agonists. At the end of the day, the final decision on stopping or tapering opioid agonist treatment rests with the patient. However, patients are often pressured by others to stop taking this medication when they’re doing well. The problem is that if they do before they’re ready, the risk of relapse is high.

“Not only is opioid agonist treatment extremely successful, but it is also incredibly cost-effective. It is estimated that every dollar spent on opioid agonist care results in $7 to $12 of savings from other parts of the health-care system and the criminal justice system. Ontario has one of the most comprehensive opioid agonist programs in the world, and we should be proud of accomplishing this on a very limited budget. It’s not easy for such a small group of physicians to reach patients throughout the entire province. One of the innovative ways addiction medicine doctors have accomplished this is by using telemedicine. Studies show that telemedicine-based opioid agonist care can be every bit as effective as face-to-face care.

“Addiction medicine is challenging, but it’s also extremely gratifying. Substance users are often a hard-to-reach population living in poverty and struggling with complex medical and mental health concerns. We are often the only contact with the health-care system for these folks, and the relationships we develop with them are important entry points for them into the health-care system. It’s one of the parts of medicine where we can see positive, life-changing results for our patients literally overnight.”

Allergy and clinical immunology

Practising doctors: 137

Allergists/immunologists specialize in the diagnosis, treatment and management of allergies, asthma and immunologic disorders.



Practising doctors: 1,474 

Anesthesiologists specialize in providing varying levels of sedation, sleep and pain management for surgery, childbirth and other painful medical procedures. Anesthesiologists also provide resuscitation and treat critical illness in emergency and intensive care departments.

From Dr. Monica Olsen, anesthesiologist and past chair of Ontario’s Anesthesiologists, a Section of the OMA:  

“Anesthesiologists care for patients during their procedure, surgery or illness. An anesthesiologist might tell their patients: ‘I am going to keep you sound asleep, safe, warm and comfortable, and fully monitored, for as long as the surgeon needs to complete the procedure.’

“Or ‘I’ll be with you the whole time and wake you up when we’re finished.’

“Or ‘I will take you to the recovery room where you’ll have your own nurse and the same monitoring you had during the operation.’

“Or ‘The recovery room is where you’ll begin the recovery process, which will result in either discharge home if you’re having a day procedure, or admission to hospital if that is planned or necessary.’

“The process of having anesthesia is like taking a plane ride with a take-off, then cruising, then landing. It’s the same whether for a surgery or procedure, diagnostic test, labour and delivery, or emergency or critical care.

“Think of the pre-op phase as checking in at the airport and showing your ticket with information about your destination: how you’ll get there, who the staff on the flight will be, and required procedures before, during and after the flight.

“Anesthesiologists prepare for each patient because everyone is unique. We meet with the patient and get their medical and surgical history, blood pressure, height, weight and oxygen levels. Knowing a patient’s normal blood pressure and oxygen levels is important because we monitor these during the procedure for any changes. The patient’s height, weight and medical history are important because we use this information to choose the right kind and doses of medication. During this patient consultation, we also have an informed consent discussion about anesthesia and its potential side effects and complications.

“While anesthesiologists need to understand and consider the needs of the patient, we also need to consider the nature of the surgery. That’s because the surgeon needs proper access and exposure to do different types of procedures.

“Armed with all this information, the anesthesiologist decides where on the spectrum of care options is best for the patient and their procedure. There can be no anesthesia, freezing (‘local anesthetic’) only, freezing with sedation, nerve blocks targeting certain areas (such as freezing one limb or the lower body during labour or joint replacement), or general anesthesia.

“One misunderstanding about anesthesia is that patients receive medication to make them fall asleep and wake up. It’s actually more complicated than that. You’ll probably receive about eight to 10 medications during a procedure. This is because we need to make sure that patients are comfortable, so we control for pain, anxiety, muscle relaxation and side effects, as well as sleepiness.

“Before the procedure or surgery starts, we select and administer medications or perform procedures to make patients comfortable or sleepy, then choose from many types of medications to maintain the patient’s comfort or sleep. We also administer several medications for pain management and nausea reduction.

“As the procedure ends, we reverse muscle relaxation and turn off the maintenance anesthesia drug. This last part requires careful timing. Using the flying analogy again: waking up from anesthesia is gradual, like landing an airplane – you don’t suddenly drop from 40,000 feet right down to the runway, but rather you gradually descend. After the procedure, you go to the recovery room, which is like getting off the plane once you land.

“As you can imagine, most anesthesiologists are based in hospitals, working in operating rooms and intensive care units, while a smaller number work in pain or endoscopy clinics or provide anesthesia for dental and plastic surgery services.

“Before becoming an anesthesiologist, we have four years of medical school followed by five years of residency in anesthesia. We receive a lot of training in physiology to understand the cellular and system level functioning of the body; and a lot of training in pharmacology, which is the science of the interaction of drugs with the human body. We also study physics and medical technology.

“Near the end of residency, anesthesiologists can choose to do additional subspecialty training called a ‘fellowship,’ in areas such as intensive care/critical care, anesthesia for cardiac surgery (heart), chronic pain management, obstetrical anesthesia (anesthetic care for women having babies), and pediatric (children’s) anesthesia.

“Anesthesiologists are available for patients 24-hours a day, 365 days a year. We attend scheduled procedures during the day, but almost all anesthesiologists will be required to provide after-hours care for urgent and emergency cases, including overnight coverage.

“While most people are at least somewhat familiar with what anesthesiologists do, COVID-19 has made more people realize that respiratory diseases sometimes mean that patients require breathing support (including intubation). Anesthesiologists are one of the most common physicians who perform these intubations. This means we have considerable exposure to COVID-19 because breathing tubes are inserted into the lungs where the virus is located. It is a critical procedure that’s needed to help these very sick patients survive. So regardless of what critical health care you need or when you need it, an anesthesiologist will always be there and ready to help you.”

Cardiac surgery

Practising doctors: 69

Cardiac surgeons specialize in the surgical care of patients of all ages with conditions and diseases of the heart, including muscle, valves and great vessels and blood vessels providing, entering and leaving the heart and lungs.



Practising doctors: 573

Cardiologists specialize in diagnosing, assessing and treating patients with diseases and defects of the heart and blood vessels (the cardiovascular system).


Chronic pain

Practising doctors: 278

Chronic pain specialists evaluate, diagnose and treat all different types of pain. This could be acute pain, chronic pain, cancer pain, pain arising from surgery, injury, nerve damage, and metabolic problems such as diabetes, or pain without any obvious cause.


Critical care medicine

Practising doctors: 277

Critical care specialists recognize and manage acutely ill adult patients with single or multiple organ system failure requiring ongoing monitoring and support.



Practising doctors: 218

Dermatologists specialize in the diagnosis, prevention and treatment of skin diseases and other skin conditions. This includes the maintenance of skin health and appearance. Dermatologists have, at minimum, five years of medical and surgical training recognized by the Royal College of Physicians and Surgeons of Canada.


Diagnostic and interventional radiology

Practising doctors: 879

Diagnostic and interventional radiologists specialize in diagnosing and treating injuries and diseases using medical imaging (radiology) procedures (exams/tests) such as X-rays, computed tomography (CT), magnetic resonance imaging (MRI), nuclear medicine, positron emission tomography (PET) and ultrasound.


Emergency medicine

Practising doctors: 1,567

Emergency medicine physicians work in hospital emergency departments and focus on the recognition, evaluation and care of patients who are acutely ill or injured.



Practising doctors: 267

Endocrinologists diagnose and treat hormone problems and the complications that arise from them. Common conditions treated by endocrinologists arise from the pancreas, thyroid, pituitary, adrenal glands, ovaries and testes.

From Dr. Farid Boutros, endocrinologist and chair of OMA Section on Endocrinology:

“We’ve all heard of hormones – most frequently in the context of teenagers – but what are they exactly, and where do endocrinologists come into the picture? Hormones are special strands of proteins that travel in our bloodstream, and there are about 50 different kinds. Each one signals different connections in and between our organs to help them function properly and work together. Hormones also control metabolism, the process by which our bodies break down food and turn it into energy. But more about that later.

“Endocrinology is the science of hormones, and endocrinologists are the specialist doctors who diagnose and treat disorders that happen when hormones get out of whack. For example, hormones control our blood pressure along with the heart through the adrenal glands, which are attached to our kidneys, so disorders from the secretions of the adrenal glands can cause high or low blood pressure. Our sex organs and genital systems are controlled through hormones to determine our sex identity at birth, puberty, sexuality, fertility and childbirth. Any disorders at that level can cause significant problems with lifestyle, and the most common is infertility – or couples being unable to have children.

“Hormonal disorders are complicated and need specialized care and treatment. Your family doctor will refer you to an endocrinologist if hormone issues turn up. Endocrinologists generally require 15 to 20 years of education to treat such a range of diseases. Because there are only about 260 endocrinologists in Ontario, the average wait time to see one of us can be four to six months. Unfortunately, this puts stress on emergency departments. Every day I see ER patients with hormone issues in much worse condition than they would have been if they received specialized treatment early on.

“The most common hormone-based disease that endocrinologists see is Type 2 diabetes, which affects over four million Ontarians. What? Diabetes is a hormone problem? I thought it’s because we eat too much sugar!

“The truth is that Type 2 diabetes happens when your body doesn’t produce enough of the hormone insulin to process all the carbohydrates and other sugary things you eat. Insulin is produced by the pancreas gland and controls how we metabolize glucose, the sugar our bodies use to manufacture energy from sugary foods. Think of glucose as the gas for your car.

“Because your pancreas only produces a limited amount of insulin each day, too many carbs and too much sugar makes your body race through the available insulin. Once the insulin runs out, your body runs a higher load of glucose. This extra glucose turns into a toxic end product. It then collects in the walls of your arteries and makes them harden. The glucose toxins can also affect the heart, eyes, kidneys and brain.

“Diabetes is serious business: it’s the number one condition that leads to heart attacks and strokes. And the higher the glucose in your body, the worse the health risks and complications.

“If you start eating better early, after you get diagnosed, you can actually reverse Type 2 diabetes. But I don’t have to change my diet because my endocrinologist gives me pills! Pills are not a cure for diabetes. We always tell patients that pills don’t replace insulin – they just balance your sugar a bit. Serious damage is still being done. To get rid of diabetes and stay healthy, you must deal with the root cause: cut back on the carbs and sugar. That why for diabetes patients, endocrinologists focus on dietary counselling early in the disease and throughout the disease management process.

“The second most common hormone disease endocrinologists see and treat is related to the thyroid, a gland in the lower part of your neck. The thyroid acts as your energy thermostat. It produces thyroid hormone that regulates heart and muscle function, energy level, fertility and sexuality. If too little thyroid hormone is produced all these functions slow down. If the thyroid becomes overactive and produces too much hormone, this can cause significant health consequences including heart disease and osteoporosis, or weak bones. An overactive thyroid is often caused when the patient is under a lot of stress. However, because thyroid issues can be caused by stress, it can also go back to normal if stress is eased.

“Endocrinologists can treat and even cure underactive and overactive thyroid problems through medication and careful monitoring. Sometimes we treat overactive thyroid by radiation in a pill form. If someone develops thyroid cancer, and we see that surgery is needed, we will refer patients to a surgeon but monitor them before and after.

“So much of how well – or not – our body works depends on how well our hormones are functioning. If your family doctor or endocrinologist diagnoses a hormone disease or imbalance, take it seriously and take the right steps to get your hormones back into synch. I guarantee you’ll feel a lot better in the long run.”


Practising doctors: 332

Gastroenterologists are physicians who are trained to diagnose and treat problems of the digestive tract and the gallbladder, liver, bile ducts, and pancreas.

From Dr. David Morgan, gastroenterologist and chair of OMA Section on Gastroenterology: 

“The word ‘gastro’ means ‘stomach.’ Gastroenterologists are doctors who specialize in your digestive system. This includes every part along the chain that food passes through, from your mouth to your bum. Gastroenterologists are sub-specialists who have already trained in internal medicine. After completing medical school, and three years studying internal medicine, we have to complete another three years of training in gastroenterology to understand this very complex system.

“There are about 400 gastroenterologists in Ontario, and most of us specialize in diagnosing and treating a different part of your gastrointestinal (GI) tract. Some gastroenterologists focus on problems with motility, which is how food moves through your system. Others focus on inflammatory bowel diseases like Crohn’s and colitis or treat the liver or pancreas, which are very important organs in breaking down and processing food. We also deal with emergencies when someone has something caught in their throat or is suddenly bleeding from somewhere they shouldn’t be. Some gastroenterologists operate in clinics, while others work in hospitals. The only thing we don’t do is surgery, but we refer you to a surgeon if you need one.

“The average time to get diagnosed with Crohn’s disease is about two years partly because of long wait times because there aren’t enough gastroenterologists. But another big part of the delay is because many people with symptoms say, “Oh, it will go away”, or fluff off their symptoms to something else, or just plain ignore them.

“I totally understand it can be embarrassing to discuss certain body parts with your doctor. But don’t be shy, talk about it! It may turn out to be something minor, but it may be something much more serious that needs to be looked at. You don’t want to die of embarrassment. So, go and see your doctor if you’re: losing a lot of weight or a big change in your bowel habits, for no real reason, your food is sticking when you swallow, and other upper GI tract symptoms, you have a big belly that looks like it’s filled with fluid or you have rectal bleeding, regardless of your age.

“Diagnosis and treatment of gastroenterological issues is light years ahead of what you’re probably imagining. This makes it a lot less scary and a lot less uncomfortable. Even in the 30 years that I’ve been practicing medicine, the progress has been pretty amazing.

“Colonoscopy is a great example. The chances of getting colon cancer in Ontario is one in 19, so, everyone over 50 should take advantage of Ontario’s colorectal cancer screening program. If you have a history of colon cancer in your family, you should have a colonoscopy. If we find large abnormal tissue growths called polyps that could develop into cancer, we can remove them without surgery by using a scope. The scopes we use are very high-tech. Some scopes feed high-resolution pictures directly to a monitor, while others are equipped with ultrasound that lets us perform biopsies and drain cysts on the spot. There are about 470,000 colonoscopies done in Ontario each year with slightly less than half of these performed by gastroenterologists (the rest are done by surgeons).

“We now have pill-sized cameras that when swallowed take 60,000 pictures during their eight-hour journey through your digestive system. This is especially invaluable because we can examine all of the small bowel in high-resolution, which isn’t possible with x-rays, and scopes aren’t long enough. But don’t worry, you don’t have to recover the camera! The photos are directly transmitted by radio to a hard drive you wear on a belt. The images are then electronically stitched together into an hour-long video that we study to see exactly what the problem might be.

“Inflammatory bowel disease, like Crohn’s, can be painful and debilitating, and Ontario has one of the highest incidences in the world. Crohn’s used to be treated by surgery, but now gastroenterologists have game-changing medications for patients such as biologics. You’ve probably seen biologics advertised on TV, but what are they exactly? Biologics are living medicine. They are large complex proteins that have to be made in a living organism and are manipulated or folded into the shape we want to block inflammation. Biologics are much more complicated medicine than a pill and not the kind of drug you can make in a test tube. It’s like comparing a bicycle to a jumbo jet.

“Thirty years ago, we didn’t know what Hepatitis C was, and now we can virtually cure it with medication. We’ve also discovered that painful peptic ulcer disease is caused by bacteria that we can cure using antibiotics.

“So how do gastroenterologists keep improving how we diagnose and treat our patients? One important way is that we, and our surgeon partners, are some of the few doctors who must report on various performance measures. Our results are measured and sent back to us through Cancer Care Ontario, and this helps us improve our training, focus and ability to measure outcomes. Ontario’s gastroenterologists are always pushing hard to help our patients!”

General and family practice

Practising doctors: 11,492

General and family practice physicians are also called family doctors or primary care physicians. They treat a variety of illnesses and conditions, conduct health screenings and comprehensive physical exams, and provide primary, wellness and preventative health care.


General internal medicine

Practising doctors: 839

Internists diagnose and manage diseases involving any organ system and are specially trained to manage seriously ill adult patients suffering from advanced illness and/or diseases of more than one system.

From Dr. Benjamin Bell, general internist and chair of the OMA Section on General Internal Medicine:

“General internal medicine physicians have been called the ‘detective agencies’ of medicine. We’re the doctors brought in to see adult patients when they’re obviously sick, but it’s not clear what’s wrong with them. We’re problem solvers, experts in diagnostic challenges, and use clues and experience to figure out the cause of the patient’s illness and find a solution.

“After completing four years of medical school, we chose the medicine track (versus the surgery track). That’s another three years when training is focused on all aspects of internal medicine, literally from top to bottom: everything from neurology to cardiology to gastroenterology. After this phase of training, many physicians choose to sub-specialize, but those of us who want to stick with the challenges of solving mysteries take another one or two years of specialized training before being qualified as general internists.

“There are about 900 general internal medicine specialists across Ontario. Most of us work in hospitals – in emergency rooms, hospital wards and hospital-based clinics.

“We’re on-call in emergency rooms 24/7, working alongside emergency room physicians. Many patients come in with an obvious problem with an obvious treatment solution, such as a broken leg. But if someone presents with a complaint that could be caused by many things, like shortness of breath, it’s probably a general internist who’s going to see them. We help determine the underlying cause and decide if the patient requires hospital admission.

“As we examine each patient and take a history, all possible causes of the symptoms are running through our heads, along with all the possible questions to rule something in or out. Shortness of breath could be caused by chronic obstructive pulmonary disease (COPD), asthma, pulmonary embolism, pneumonia, heart failure, sepsis, amongst many other possibilities. Is there cough, mucus, or fever? That could signal pneumonia. Does the patient have swollen ankles or chest pain? That could point to a heart attack.

“Our exam and questions narrow down the possibilities, then we order appropriate lab work and imaging right away to get more information. For example, if the patient may be having a heart attack, blood work would include checking for cardiac enzymes. We’d also order an electrocardiogram and a chest x-ray, and maybe a CT scan. The results from these tests might confirm our working diagnosis, or they could put us on a different track altogether.

“General internists are not just in emergency rooms. If you’ve been admitted to the hospital for a general complaint and a doctor visits your room to check on you, he or she may be a general internist.

“About one quarter of general internists also work in clinics where we mostly see patients referred by their family doctors. These patients may have already been diagnosed and getting treatment, but the treatment that should be working just isn’t. Something else is going on – but what?

“Here’s an example: A patient has high blood pressure, and their family doctor prescribes a medication that lowers high blood pressure. But the patient is having unusual side effects, or the blood pressure remains high. The family doctor changes the medication, but still, the patient’s blood pressure isn’t coming down. The family doctor suspects there may be something triggering the high blood pressure in the first place and refers the patient to a general internist.

“Sometimes finding and resolving that cause cures the patient. It could be that the patient in this situation has a mass on their adrenal gland. This type of mass can cause high blood pressure as a side effect, so we’d check for this on our list of possible underlying issues. If this turns out to be the case, then surgically removing the mass may cure the high blood pressure. While we’re the experts at diagnosing more complicated issues, we usually refer the patient to the appropriate subspecialist for treatment. In this example, the patient would be referred to a surgeon to have the mass removed.

“It can be very worrisome and stressful for patients and their families when someone is sick but doesn’t know why. As general internists, we can tell a patient, ‘The mystery is solved. We’ve figured this out, we know what’s causing your distress, and we have a plan to deal with it.’ That’s the most rewarding part of our job.”

General surgery

Practising doctors: 682

General surgeons are trained in the diagnosis and preoperative, operative, and postoperative management of patient care. General surgeons provide surgical care for the whole patient.


General thoracic surgery

Practising doctors: 504

Thoracic surgeons specialize in the surgical management of disorders of the heart, lungs, esophagus and major blood vessels of the chest.


Genetics medicine

Practising doctors: 51

Geneticists diagnose and treat families with medical issues including single or multiple birth defects, sensory deficits (like hearing loss or blindness), learning disabilities and developmental delay, errors of metabolism, problems with growth and disorders that run in families such as cancer and high cholesterol.

From Dr. Andrea Guerin, geneticist and vice-chair of OMA Section on Genetics:

“Genetics is the science of understanding our genes, how they work, and how they influence our health. The medical geneticists in Ontario specialize in helping patients of all ages that are suspected of having a health problem due to a change in their genes. We work with patients to determine the right test to make the diagnosis, counsel you on what that means for you and your family and help manage the disease.

“But what is a gene anyway, and what does it do?

“Genes are the instructions or the blueprint of your body. They make proteins, which carry out the day-to-day functions that keep your body working. Genes can be passed down from parents to children and determine traits such as your eye colour or how tall you are. However, not all genetic conditions are inherited – it is possible to have a change in your genes that is brand new in you alone.

“Genetic diseases are caused when these instructions do not function the way they should. Sometimes it is because there is not enough of the protein product to perform a task in your body, and sometimes it is because the gene works in a way that it shouldn’t. These genetic diseases can show up at any time in a person’s lifetime.

“All newborns in Ontario are screened for common genetic disorders, so we can treat them early and prevent irreversible complications. For example, phenylketonuria (PKU) is a genetic disease where a baby’s body can’t break down some of the protein components found in food. If these components build up, they can damage the baby’s brain irreversibly. When a medical geneticist determines a baby has PKU, the baby is put on a special diet that reduces these kinds of proteins but also allows the baby to grow.

“A person might come in with a health issue that turns out to have a genetic cause, often after many other consultations, and potentially years of searching for an answer. Medical geneticists solve mysteries for those patients whose symptoms don’t add up. We also treat the whole family – and sometimes save lives. We also advise on the future generation and provide prospective parents with risk assessments for genetic diseases.

“Genetic tests are generally done usually through blood work at the hospital. Many tests need to be sent elsewhere as they are complicated and are only done in certain labs. Unfortunately, it can take many months or even longer to get testing done. The tests are complicated to arrange and interpret, and more and more we are seeing genetics as the potential cause of diseases, so the volume of patients where genetic testing is helpful has increased. The number of medical geneticists in Ontario is not big, and it has not kept up with the demand for genetic testing. We do our best to see patients in a timely manner, and help our physician colleagues become familiar with genetic testing, so they can arrange it when appropriate to provide patients with the best care.

“While genetic tests are an important part of the process, the first thing medical geneticists do when we see a patient for the first time is take a medical and family history and do an appropriate physical exam. We also discuss the meaning of the test and the patient’s feelings around the test and result. Genetic tests cannot always be interpreted as ‘yes’ or ‘no’ and a result may have a big impact on the patient, their future and their family members. Understanding what the results mean for you is very important. Then we interpret the tests based on the patient. It takes years of training and even the most experienced medical geneticist is constantly learning. That is one of the most exciting things about medical genetics, how quickly it advances.

“People ask me all the time about home genetic testing kits. My advice is the same as with any other medical test: you should only do tests that are medically indicated, and any results must be in the context of the whole patient and their health. We don’t treat lab results, we treat patients, and every patient is different.

“The field of genetics is relatively new and very complex. That is why it’s important to see your family doctor and get a referral to a medical geneticist if you’re concerned about a genetic disease. We can try to find the answers you need so that you can make the best decision for yourself and your family.”

Geriatric medicine

Practising doctors: 131

Geriatricians are physicians who specialize in care of the elderly and the diseases that affect them. Their approach tends to be holistic and involves a multidisciplinary team.


Hematology and medical oncology

Practising doctors: 427

Hematologists/medical oncologists specialize in diseases of the blood and blood components, including blood cells and bone marrow cells. Hematological tests can help diagnose anemia, infection, hemophilia, blood-clotting disorders, and leukemia (cancer of the blood).


Hospital medicine

Practising doctors: 357

Hospitalists specialize in providing comprehensive wrap-around care for admitted patients 24 hours a day. As the most responsible physician, they collaborate with multidisciplinary teams including allied health professionals and consulting specialists, to co-ordinate the best possible care plan for their patients throughout the course of an admission. They serve as the point of contact for communicating health-care decisions, facilitating access to consultants, and supporting safe and seamless transitions to the community.


Infectious diseases

Practising doctors: 165

Infectious disease specialists focus on diagnosing and treating complex infections, including chronic infections such as HIV. Infectious disease specialists also participate in the control of infectious diseases in the health-care environment, mitigating antibiotic resistance through stewardship, dealing with infections in complex patients such as transplant and cancer and the management of tropical infections.


Laboratory medicine

Practising doctors: 558

Laboratory medicine specialists, also called clinical pathologists, diagnose disease through the laboratory analysis of bodily fluids and tissues, including blood and urine.


Long-term care/care of the elderly

Practising doctors: 89

Long-term care physicians specialize in helping patients who cannot live independently or perform everyday activities on their own. Many work in long-term care facilities as medical directors and attending physicians.



Practising doctors: 249

Nephrologists specialize in kidney care and treating diseases of the kidneys and fluid and electrolyte imbalances. Nephrologists are educated in internal medicine and then undergo additional training.



Practising doctors: 424

Neurologists diagnose, treat, and manage disorders of the brain and nervous system, including Alzheimer’s disease, amyotrophic lateral sclerosis (ALS), concussion, epilepsy, migraine, multiple sclerosis, Parkinson’s disease and stroke.



Practising doctors: 81

Neuroradiologists specialize in diagnosing abnormalities of the central and peripheral nervous system, spine, and head and neck using x-rays, CT (CAT) scanners, magnetic resonance imaging (MRI) scanners, and ultrasound machines.



Practising doctors: 78

Neurosurgeons, also known as brain surgeons, specialize in the surgical treatment and management of conditions that affect the brain, spine and nervous system.


Nuclear medicine

Practising doctors: 59

Nuclear medicine radiologists use radioactive materials, called radiopharmaceuticals, to produce images of the body's organs to diagnose and treat disease.


Obstetrics and gynecology

Practising doctors: 761

Obstetricians specialize in the health of pregnant women, including delivering babies. Gynecologists specialize in the female reproductive system. OB-GYNs specialize in both obstetrics and gynecology and are trained surgeons who can perform a wide range of procedures.


Occupational and environmental medicine

Practising doctors: 70

Occupational and environmental medicine specialists focus on recognizing work-related diseases and injuries and diseases due to harmful environmental exposures and their management. They also deal with various conditions affecting the ability to work and health promotion and disease prevention in the workplace at an individual and group level. These specialists recognize and deal with workplace and environmental hazards and help organizations optimize human capital performance and improve productivity in the workplace.

From Dr. Aaron Thompson, past chair OMA Section on Occupational and Environmental Medicine, staff physician at St. Michael’s Hospital Division of Occupational Medicine, chief medical officer for the Workplace Safety and Insurance Board (WSIB), program director for the Occupational Medicine Residency Program at the University of Toronto:
Keeping Workers Healthy

"In Ontario, over 200,000 workplace injuries and illnesses occur each year. These range from minor injuries to permanent life-altering health conditions such as cancers, which can often go unrecognized. Identifying them requires a careful exposure history by a physician with an in-depth understanding of the workplace environment. Occupational medicine physicians are specialists who are trained to assess and manage such work-related conditions with a focus on preventing health effects from harmful environmental exposures. We assist with diagnosis, advise on the appropriate filing of workers compensation claims and provide guidance to help people with impairments return to work and stay actively employed.

Some physicians in this field are occupational medicine specialists who have fellowships from the Royal College of Physicians and Surgeons of Canada (FRCPC). As well, many physicians from other medical disciplines such as family medicine have gained additional expertise in the field through experience and training, which is then recognized by certification by the Canadian Board of Occupational Medicine (CBOM). In stark contrast to many other industrialized countries, Canada has remarkably few occupational medicine physicians. Even combining those certified with either FRCPC and CBOM, the total number is low. The problem with this is that there may be long delays in identifying occupational illnesses and injuries, resulting in permanent health conditions that could have been prevented. Even worse, without occupational medicine sometimes conditions may go entirely unrecognized. Timely diagnosis not only helps to prevent diseases and physical disabilities, but it also helps to prevent other people from being exposed in the first place.   

"Occupational medicine physicians work in a variety of settings. Some of us have practices where we see patients referred by family or specialist physicians to diagnose and provide advice on the management of work-related injuries and diseases. Some of us also work directly with companies in their occupational health departments to ensure workplaces are safe, to monitor for early signs of occupational illnesses (medical surveillance) and to facilitate the return to work for people that need accommodations. Finally, occupational medicine physicians also work in provincial and federal government positions, such as the Ministry of Labour, Public Health Ontario or workers’ compensation boards. 

"Workplace hazards are classified as chemical, biological, physical, ergonomic or psychological. Chemical hazards include substances such as solvents, which can cause skin and respiratory irritation as well as various diseases. Biological hazards include things like viruses, bacteria and mould. Health-care workers may have a greater risk of exposure to hazards like COVID-19, while lab workers can be exposed to allergens from animals. Physical hazards include things like hot and cold temperatures, noise and radiation. Ergonomic hazards from repetitive, forceful movements or prolonged awkward postures occur in many settings, from office work to heavy construction. Psychological hazards range from acute traumatic events (seen in first responders for example) to chronic mental stress, workplace harassment and bullying.

The hazards in your workplace depend on the type of work you do. Some workplace hazards are common and easy to identify, such as hot or cold temperatures, certain chemicals or ergonomic hazards such as repetitive lifting. Other exposures may less obvious, such as carbon monoxide or ingredients in cleaning products that can cause skin allergies. Although low-level exposures to many substances are generally safe, it’s always “the dose that makes the poison,” so when symptoms develop, it is important to ask whether exposures at work may be the cause.  

"Environmental medicine is a component of occupational medicine. Injuries and illnesses may result from hazardous exposures both at work and from the environment in general. In many cases, the exposures are the same but may differ in the level of exposure (dose). For example, arsenic exposure may occur both in a worker that processes pressure-treated wood and in a person that unknowingly burns pressure-treated wood at a campfire, but the level of exposure likely differs dramatically. Another example is radiation exposure in industrial applications versus radon exposure in a residential home. Regardless of whether the exposure takes place at work or during non-work activities, occupational medicine physicians are experts in assessing illnesses and injuries to determine what the causative exposure is and how it can be minimized or eliminated."

How does an occupational medicine assessment differ from other medical assessments?

"Although occupational medicine physicians conduct a general medical assessment similar to other types of medical consultations, they also take a very detailed work and exposure history to identify possible causative exposures. This can make a big difference in care and recovery. Here is a case example: A patient develops abdominal pain, fatigue and mental fogginess which eventually progresses to more severe illnesses such as anemia (low blood cell counts), kidney and nervous system problems. Because the symptoms are not specific and an occupational cause was not suspected, the patient undergoes a number of tests, some invasive like colonoscopy or imaging that exposes them to radiation to try and find the cause. It is only when the detailed occupational history is taken, sometimes months or even years after the onset of symptoms, that an occupational exposure is identified that explains all the symptoms from the start (in this case the metal lead). Had an occupational exposure been suspected earlier, the invasive testing and prolonged illness could have been avoided, the exposure would have been minimized or eliminated, and the patient would have recovered. This case illustrates the importance of considering occupational and environmental causes for injuries and illnesses and referring to occupational medicine physicians to help identify and manage these diseases and injuries.

"Wherever you are working, be aware of potential hazards in your workplace and stay safe. Be sure to tell your family physician the type of work you do – this can speed up diagnosis and prevent ongoing exposure. When questions remain about whether the cause of your injury or illness is from exposure at work or in the environment, occupational medicine physicians are here to help."


Practising doctors: 406

Ophthalmologists diagnose and treat all eye diseases, perform eye surgery and prescribe and fit eyeglasses and contact lenses to correct vision problems. Because they are physicians, ophthalmologists sometimes recognize other health problems that aren’t directly related to the eye and refer those patients to the right medical doctors for treatment.

From Dr. Rajinder Rathee, eye physician and surgeon, past chair of Eye Physicians and Surgeons of Ontario:

“Most of us don’t think about how much we rely on our sight – until we’re at risk of losing it. Blindness is generally a patients’ second-biggest health-related fear after cancer. Simply put, Ontario’s 400 ophthalmologists are the doctors who save sight. We specialize in diagnosing and treating eye diseases and performing eye surgery. Ophthalmologists are the medical doctors specializing in eye care that the other eye care and health professionals refer their patients to when exams turn up serious issues. And since almost everyone knows someone with a serious eye issue, ophthalmologists are one of the most commonly known medical specialists.”

Blinding accidents happen in the blink of an eye

“Threats to our vision can happen to anyone, at any stage of life, either by trauma or disease. The good news is that today ophthalmologists can treat most of them successfully.

“Every time I’m on call, I see patients of all ages with serious but preventable eye trauma. Most are caused by industrial accidents, or through sports injuries. Play injuries – like a ball or toy in the eye – or shattered glass are also common. Fights not only cause injuries to the eye but also cause broken bones around the eye which can lead to a secondary injury.

“Ophthalmologists can often save a cut or damaged eye through surgery. Other times, we can repair the eye itself but not the vision in that eye. But sometimes we can’t save the eye at all. That’s why eye protection is so important, especially for industrial and construction workers and athletes. And of course, like my mother used to say, play safe and don’t get into fights!”

Eye diseases can be slowed, even stopped – so go see your doctor

“Vision develops in childhood. If eye issues aren’t caught and fixed by the age of nine, children can suffer permanent vision loss – and a radically different life. Ophthalmologists treat children of all ages, from premature babies who have abnormal blood vessels, to older children with strabismus (misaligned or crossed eyes) or amblyopia (lazy eye).

“Diabetes can happen at any age. One of the most devastating but unknown effects of diabetes is bleeding in the eye that leads to vision loss. However, if we see patients early, we can treat them with lasers or injections.

“Every one of us will develop cataracts or cloudy lenses. The cloudier the lens becomes, the harder it is to see through it. Ophthalmologists remove the cloudy lenses and replace them with new ones using ultrasound to make microscopic incisions. It dramatically improves vision, and most people don’t need glasses as much as they did before surgery.

“Have you ever had a test where a puff of air is blown in your eye? This checks for high eye pressure, which means you could have glaucoma. Glaucoma is called the “silent thief of sight” because you don’t even feel it and only an eye test can find it. The high pressure first causes tunnel vision. If left untreated, the pressure increases and can lead to total blindness. If caught early, an ophthalmologist can stop glaucoma in its tracks with eye drops that lower eye pressure.”

Hi-tech restores sight

“Technology has changed the world, and it’s no different for ophthalmology. Before 2005, we treated patients with thermal lasers. They slowed the progress of diseases like diabetes, cataracts and glaucoma, but we couldn’t restore vision that was already lost. It was very frustrating that our patients lost some independence because they could no longer drive or read.

“But that all changed in the mid-2000s with drugs that could be injected right into the eye. Yes, that’s a cringe-worthy image, but it’s been a real game-changer for patients. More than 50,000 Ontarian’s have relied on injections to regain some or all of their lost vision.

“Macular degeneration is the loss of central vision when the macula (the central area of the retina) gets thinner or starts to bleed. It’s very common in older patients. This is another eye disease where new technology has made the world of difference. Not that long ago, there was no treatment at all, but today injections can maintain or even improve sight.

“The fact that ophthalmologists can now slow, stop and even restore vision loss means it’s very important to have regular eye exams and visit your doctor if you’re having vision problems. You can see that, right?”

Orthopedic surgery

Practising doctors: 610

Orthopedic surgeons specialize diagnosing and treating disorders of the bones, joints, ligaments, tendons and muscles. Some orthopedists are generalists, while others specialize in certain areas of the body, such as the hip and knee, foot and ankle, shoulder and elbow, hand, or spine.


Otolaryngology/head and neck surgery

Practising doctors: 265

Otolaryngologists/head and neck surgeons commonly referred to as ear, nose, and throat doctors (ENTs), treat diseases of the head and neck, both medically and surgically. This includes diseases of the external, middle, and inner ear, the nose, oral cavity, neck and facial structures.


Palliative medicine

Practising doctors: 241

Palliative medicine physicians specialize in the care of patients with life-limiting illness and their families. They support the emotional, medical and physical well-being of their patients throughout the dying process.



Practising doctors: 1,328

Pediatricians manage the health of children and teens, including physical, behaviour, and mental health issues. They are trained to diagnose and treat childhood illnesses, from minor health problems to serious diseases.


Physical medicine and rehabilitation

Practising doctors: 219

Physical medicine and rehabilitation specialists, also called physiatrists, evaluate and treat patients whose functional abilities have been impaired because of injury or disease. They clarify the diagnosis, assess physical impairment, provide medical treatment and organize and integrate a wide range of rehabilitation therapies.


Plastic surgery

Practising doctors: 219

Plastic surgeons specialize in the restoration of function and form (appearance) following deficits caused by trauma, illness, or congenitally acquired differences. Some plastic surgeons may sub-specialize in areas like aesthetics, breast reconstruction, burns, craniofacial, gender confirmation, hand/peripheral nerve, skin cancer and complex wound care/reconstruction.


Primary care mental health

Practising doctors: 189

Primary care mental health physicians are family doctors who devote a substantial portion of their practice (20 to 50 per cent or more) to mental health work.

From Dr. Nicola Yang, family doctor and vice-chair of OMA Section on Primary Care Mental Health:

“According to the Canadian Mental Health Association, one in five people in any given year will personally experience a mental health problem or illness. During COVID-19, that number is growing. This pandemic is affecting everyone – but what can you do? Reach out to your family, friends, and other supports to share and talk. If the situation is becoming serious, consider talking to a doctor about help that might be available to you, including from a primary care mental health physician.

“About 90 per cent of primary care mental health physicians are family doctors who devote a substantial portion of their practice (20 to 50 per cent, or more) to mental health work, but some specialists incorporate psychotherapy into their practice. In addition to the many years of training we receive in medical school and residency, we strive to keep ourselves up to date with psychotherapy or mental-health-related continuing education. Many of us also take part in additional training and supervision for different types of psychotherapy. This is important because, in the case of therapy, it’s rarely one-size-fits-all, and having training in different therapies lets me put together a treatment plan that’s better tailored to a patient’s unique needs.

“I started by saying you should talk to a physician because mental health and physical health are not separate. When you’re stressed or depressed, this can often come out as physical symptoms. You might panic easily, have problems sleeping, struggle to get out of bed, lose concentration, or make more mistakes at work. Often, the intensity of our emotions can manifest as stomach issues, headaches, pain, chest discomfort, nausea, or even vision problems. This is especially true for people who aren’t very aware of their emotions or have learned to suppress them.

“So, while it’s important to make sure your symptoms aren’t the result of a physical condition, it’s not uncommon that many physical symptoms have a mental health component. In fact, up to 50 per cent of patients present to their family doctors with physical symptoms that cannot be explained by a general medical condition alone. And just because your symptoms have a mental health component does not make them any less real or painful.

“Everyone can have a bad day (or even a bad week) or get anxious – sadness and anxiety are normal emotions. But if these feelings persist and are severe and impact your ability to work, leave the house, or function, then it’s become a problem. If not addressed, it will almost always get worse; not only will it affect your life, but also that of your family and loved ones. That’s why it’s so important to talk about it.

“Unfortunately, many patients are hesitant to bring this up with their doctor. They’re worried about stigma, that their concerns will be dismissed as, ‘it’s just in your head,’ or even that they are somehow a burden to their doctor who, ‘has better things to do.’ Never think of yourself as a burden – it is a privilege for us to journey with our patients, especially in a difficult time.

“So, please, talk to a doctor about your mental health. If your doctor thinks you’ll benefit from more intensive or specific psychotherapy, talk to them about a referral. We’re here to help through individual or group therapy.

“About group therapy – many patients are very apprehensive at first about sharing their problems with strangers, but after one or two sessions, they tell me how great it feels to finally realize that they’re not alone in their struggles.

“One of the main reasons why I chose to practice psychotherapy is because my services are generally covered by OHIP, just like psychiatrists. Even though psychotherapy is often a first-line recommendation for mental health conditions, it can be expensive, and my colleagues and I work with many people who simply can’t afford therapy with a psychologist or social worker, or don’t have insurance coverage. Unfortunately, due to high demands and funding issues, our waitlists do tend to be quite full.

“Finally, here are some things you can do to protect your mental health, especially during the pandemic:

  • Get quality sleep: Try sleeping and waking up at the same time, each day. Don’t use screens in bed and for at least one hour before bedtime, especially if you have problems sleeping. Use your bed only for the three s’s: sleep, sex and if you’re sick.
  • Balanced eating: Eat a balanced diet and regularly scheduled meals. Be mindful of eating junk food or anything with a high sugar content and set limits, for example, a treat once in a while is OK!
  • Physical activity: That can be challenging these days, but my advice with the pandemic is to stay safe, but don’t always stay indoors. Even walking around your home or neighbourhood for a few minutes and getting some fresh air helps enormously. Sunlight is especially important now that it gets dark sooner.
  • Just do it: Do something for yourself, even if you don’t feel like it. Motivation often comes after action: think about a time you didn’t want to exercise but did so anyway – you were probably glad you did it, after the fact. Being motivated is especially hard if you’re depressed. Try taking small steps to do pleasurable activities that you enjoy like taking a hot bath or reading. Try mastery activities which is something that makes you feel accomplished like doing laundry throughout the week. Continuing to do them will help you start feeling better.
  • Stay connected: Meet with family and friends by phone or video, even if you’re physically distanced – or see them from afar! Try doing an activity or learning something new with a group through phone or online platforms.
  • Parents: Try to make time for yourself – even if it means keeping the kids preoccupied enough for just a few minutes or keeping an eye on them from afar. You deserve to do something kind and nice for yourself.
  • Give yourself credit: You’ve adapted to so much despite the challenges – take credit for all the things you’re doing (even if it’s to stay afloat) no matter how ‘small.’

“Life can be stressful, and COVID-19 has added to this stress in many ways. No one is invulnerable to mental health struggles, but there is help available to turn it around.”


Practising doctors: 1,980

Psychiatrists work in a variety of settings and manage a broad range of mental health experiences. They identify and treat mental disorders and promote mental wellness. Evidence-based approaches include the use of psychotherapies, medication and neurostimulation. Psychiatrists spend 13 to 14 years in training to become experts in mental health and mental wellness, deliver comprehensive care for their patients and guide understanding human behaviour.

From Dr. Renata M. Villela, psychiatrist and vice-chair of OMA Section on Psychiatry:

“Social isolation, financial pressures, concerns about your own or a family member’s health – all these stressors can lead to mental health issues, even in normal times. The COVID-19 pandemic has shown us that people can develop depression/anxiety under challenging circumstances or can see existing mental health issues get worse. Psychiatrists continue to be here to help our patients navigate and manage mental illness, with our unique skills being especially needed now.

“Ontario’s roughly 2,000 psychiatrists are not like the stereotypes we know from the movies: cold, detached people who all look the same. The reality couldn’t be more different. What’s wonderful about the trend in medicine generally, and in psychiatry is that many more women and cultural groups are being represented in the field. This shift is helpful for patients who can see themselves reflected in their doctor, particularly in Ontario, where we are so multiculturally diverse.

“While most psychiatrists work in the community treating patients from their offices, many are affiliated with a hospital or other organization. In addition to their clinical work, they often also supervise medical students and residents and research different treatment approaches or new ways to understand how the brain works. Many people are confused by how psychiatrists differ from other mental health-care professionals. Psychiatrists are medical doctors. Before we can practice as psychiatrists, we complete four years of medical school and then five years of specialist residency training. This medical education helps us to better understand the whole person and how the mind and the body are connected. By identifying the physical problems that could be causing or contributing to mental health issues, we can make use of the full range of ways to help patients, such as medication and therapy.

“But just because psychiatrists can prescribe medication that doesn’t mean medication is our go-to treatment. As doctors, psychiatrists take a broad view of the entire patient, then match the treatment plan to what can be the best fit for that individual. We give patients information to help them make informed treatment choices from a set of options, which could mean therapy, medication, social resources and beyond. Therapy can come in several forms. Short-term therapy takes several weeks. It provides tools and new ways of thinking that can be incorporated as life skills. It can involve gathering more information about a problem, providing grounding structure in the day, or expanding social connections. Long-term therapy takes a deep dive into a person’s life, understanding major events in their past life trauma. We help get patients to a place where fear no longer controls them, and they can engage with their world differently, without repeating the same problematic patterns.

“That’s not to say someone simply ‘gets over’ a trauma. Trauma is rooted in deep biological processes where patients’ brains have a disorganized response. That means aspects of the trauma can be vividly remembered or can be experienced as memory gaps. It’s hard to make sense of the world when you feel like your mind is not cooperating. Long-term therapy can help put those puzzle pieces back together.

“Treatment decisions can also involve addressing patient concerns about being on medication in the context of stigma or existing health issues. There are more medications available today which can also have fewer side effects compared to in the past.

“There are various ways in which people respond to a global stress like the COVID-19 pandemic, from those on the milder end to people who have more severe symptoms. The pandemic can also make existing problems worse. People with obsessive-compulsive disorder, for example, can have a lot of rituals around avoiding or cleaning off germs. During the pandemic, some have felt like these rituals have been protective, which is validating as actions like frequent handwashing have become normalized. People with past trauma can feel particularly trapped by the physical distancing in place during the pandemic, which can be destabilizing for them. Having regular contact with a psychiatrist can help prevent problems from escalating. Fortunately, more format options for mental health care such as video and telephone calls are now available.

“Unfortunately, urgent situations still happen and many people who are in distress because of serious mental illness are afraid to go to the hospital these days. By the time they eventually get to the hospital, they can be in a much worse state. If you or someone you know is having any kind of medical crisis, going to the emergency department is still important. Stigma and myths around mental illness are also big barriers to people seeking help. Just because you can’t see the physical cause of mental illness – as you would with a broken leg – that doesn’t mean it is any less real or any less debilitating to the patient. You should seek help in the same way you would for any other medical problem. Whether through an in-person or a remote appointment, psychiatrists are here to help you deal with the medical issue of mental illness.”

Public health physicians

Practising doctors: 126

Public health physicians focus on the health of an entire population by preventing disease within a community. They analyze and assess public health problems, develop strategies and programs to prevent disease or promote good overall health, and consult with the public.


Radiation oncology

Practising doctors: 201

Radiation oncologists use ionizing radiation and other technology to treat malignant and some benign diseases They may also use computed tomography (CT) scans, magnetic resonance imaging (MRI), ultrasound, and hyperthermia (heat) to help with treatment planning.


Reproductive biology

Practising doctors: 58

Reproductive biology specialists treat and advise on issues that may be impacting a couple’s or a person's ability to conceive a child. This may include fertility testing, ovulation induction, laparoscopic, open surgery and assisted conception like in vitro fertilization (IVF).


Respiratory disease

Practising doctors: 287

Respirologists diagnose and treat conditions that affect the respiratory (breathing) system, including the nose, throat (pharynx), larynx, windpipe (trachea), lungs and diaphragm.

From Dr. Neil Maharaj, respirologist and chair of OMA Section on Respiratory Disease:

“Respiratory disease specialists (respirologists) mostly diagnose and treat diseases of the chest relating to the lungs or airways. We also deal with other problems related to lung function such as breathing and sleep disorders, and diseases of blood circulation within the lungs and/or diseases of the lining of the lung. Many of us also treat critically ill patients in critical care, including COVID-19 patients.

“While airway and lung problems can make it hard to breathe, they can also impact life-giving oxygen getting to all parts of the body. There are some of the common problems that respirologists diagnose and treat:

  • Chronic obstructive pulmonary disease (COPD) is the most common disease we see. It’s the number one cause of admission to hospitals apart from pregnancy, but it’s also largely preventable because it’s primarily caused by tobacco smoke. Over time, chronic smoking destroys your lung tissue until you become markedly short of breath, fatigued with little activity, and prone to respiratory infections. Using oxygen and inhaled medications can help patients breathe better in the short term, but unfortunately, there’s no cure for COPD and it will get worse over time.
  • Excessive snoring and sleepiness not only impact your day-to-day functioning but could be related to sleep apnea. This is where airways become collapsed or narrowed when you’re asleep. Excessive snoring may seem like a small thing (other than irritating the people you live with), but sleep apnea could lead to cardiovascular problems such as heart attacks or strokes, so it’s important to get it checked out. Your family doctor might refer you to a sleep physician, most of whom are respirologists. The next step is often a sleep study where your sleep is monitored overnight in a special lab. If you have sleep apnea, a CPAP machine may be prescribed that forces air down to keep your airway open. Better sleep equals better health!
  • Asthma is a fairly common disease where the airways constrict and make it hard to breathe. Asthma affects both children and adults. Symptoms can include a cough that is not resolving, shortness of breath especially when exposed to allergens, and difficulty breathing in winter when exposed to cold air. To diagnose asthma, we often give patients a test that measures how well the lungs perform. Asthma is treated with inhaled and injectable medications.
  • Lung cancer is the most common cancer in Canada. Symptoms can include a cough that doesn’t go away, coughing up blood, shortness of breath, unexplained weight loss or fatigue, lack of appetite, or a hoarse voice. When a patient is referred for diagnosis to a respirologist, we will do a chest x-ray, and other tests to investigate the cause of your symptoms. This could include a biopsy where a small sample of tissue is taken for examination. If the results are unfortunately positive, we refer the patient to an oncologist and/or surgeon for treatment.
  • Pulmonary hypertension is where the blood pressure around the lungs is abnormally high, making it hard to breathe. This can be caused by a heart problem, an abnormality in blood vessels supplying the lung, or sometimes blood clots that have travelled to the lung. We will diagnose the patient using an x-ray, CT scan, or echocardiogram of the heart. Treatment includes specialized medications to lower blood pressure and oxygen however, a healthy lifestyle is a good preventive measure.
  • Approximately 15,000 Canadians are living with fibrotic lung disease or scarring of the lungs. These patients are amongst the sickest in our entire health-care system, requiring frequent hospitalizations, advanced medications, oxygen therapy and potentially lung transplantation.
  • Transplant respirologists are the core of the world-leading Toronto Lung Transplant program at the University of Toronto, which performs 200 transplants each year. They see patients with advanced lung disease to determine if they can benefit from transplantation. They help these extremely sick patients prepare for transplant and are responsible for their care in the hospital after lung surgery and then for the rest of their lives.
  • In hospital, respirologists treat critically ill patients who have gotten sick to the point where they need advanced treatment, breathing support, a ventilator, or other treatments. This includes COVID-19 patients.

“COVID-19 has changed everything for respirologists as there is an overwhelming number of patients sick enough to be hospitalized or in Intensive Care. COVID-19 causes the lungs and airways to become inflamed. These patients that are sick enough to be in hospital will get extra oxygen and may need to on a ventilator. The ventilator acts as a temporary lung replacement and supports the patient’s breathing until they recover. They may also get medications such as steroids to reduce inflammation.

“Unfortunately, COVID-19 can have a lasting impact on some patients. Even after the infection is gone, there can be scarring of the lungs that continue to make it hard to breathe. Some patients who were fine before getting COVID-19 may need ongoing oxygen to function. That’s why it’s so important to reduce the spread of COVID-19 – there’s no way to tell how sick someone might get. To protect yourself and others, maintain physical distancing of two meters (six feet) from those not in your immediate household, wear a mask indoors and when you can’t physically distance and wash your hands often.

“There are also ways to protect yourself against many other respiratory diseases:

  • Get vaccinated for flu and pneumonia. Every senior should get the flu vaccine once a year, and the pneumonia vaccine is given once in a lifetime.
  • Many people don’t consider vaping smoking, but vaping also causes lung damage over time, especially in young people whose lungs are still developing.
  • Smoking marijuana is also a hazard to the proper health and functioning of your lungs and, like tobacco, should be avoided when possible.
  • If you’re working in an occupation where things might be inhaled, you may need to wear a mask or respirator.
  • If you live in an older home with a wood-burning stove, your lungs can be affected by being continually exposed to the smoke.

“The only thing you should inhale is clean air!”


Practising doctors: 228

Rheumatologists diagnose and treat musculoskeletal disease and autoimmune conditions commonly referred to as rheumatic diseases. These diseases can affect the joints, muscles, and bones causing pain, swelling, stiffness and deformity.


Sport and exercise medicine

Practising doctors: 156

Sport and exercise medicine specialists treat patients who have had injuries or ailments from doing exercise or who have a condition that prevents them from doing exercise.

From Dr. Lindsay Bradley, sports and exercise medicine specialist, past chair of OMA Section on Sport and Exercise Medicine:

“As a sport and exercise medicine specialist, which of these people do you think is most likely to be one of my patients: a professional hockey player, a member of Canada’s Olympic rowing team, a runner training for her first marathon, or a 60-year-old man with arthritis in his knee who finds it painful to exercise?

“The reality is that all of them are likely to be my patients, especially the 60-year-old. Most are regular folks who have had injuries or ailments from doing exercise, or who have a condition that prevents them from doing exercise. They can range in age from six to 106 with a huge variety of ability levels, and sports and exercise medicine specialists can help them all.

“Most patients are referred to us by family physicians or other specialists like an orthopedic surgeon who sees non-operative treatment as a better option than surgery for that case. On the patient’s first visit, we talk about their injury as well as their medical and activity history. I examine the area that is causing them discomfort thoroughly, as well as their general physical condition. We discuss different treatment options for their injury or issue including an exercise prescription with guidelines on what is safe for them to do, and specific recommendations about how to progress. There are treatment options for every condition, but exercise is universal – I’ll always prescribe it as a part of the treatment for all injuries. No matter a patient’s health situation, there is something everyone can do, and I’ll work together with the patient to find out what that is.

“Sport and exercise medicine specialists believe that exercise is medicine, and we can help family physicians and patients develop exercise prescriptions for many conditions. It's a proven fact that exercise helps prevent many chronic diseases like osteoporosis, osteoarthritis, diabetes, high blood pressure and high cholesterol. While some of these conditions may result from genetics and other factors, exercise can decrease their severity or prevent complications until you’re older. If you’ve already developed one of these conditions, like high blood pressure, prescribing exercise may not be able to cure you, but it might cut your medications in half!

“Exercise is especially valuable as we age. It benefits all our body systems, helps with fall prevention and balance, increases muscle mass which otherwise naturally declines, and helps with osteoporosis because bone health improves with weight-bearing activity. Exercise also acts as prevention and treatment of mental health issues – because when you do physical activity, it changes the nerve transmitters in your brain.

“We all know we should exercise, but the trick is how to turn that knowledge into action and get started. The key to a successful exercise program is finding something you enjoy. There’s usually something for everyone, so it’s just a matter of finding out what that is. The truth is that you’re probably already doing exercise but don’t know you’re doing it, like walking your dog. That’s why sports and exercise medicine physicians tailor the prescription to the person, just like doctors would tailor any other medication to your specific health situation.

“But here’s what you shouldn’t do: if you’re experiencing pain, a little bit may be ok, but don’t just power through it unless you have it checked out first, particularly if you’ve had a head injury or concussion. A sport and exercise medicine physician will let you know the appropriate level of pain that you should be experiencing.

“Most sport and exercise medicine specialists are family doctors with extra training in sports medicine, which is usually a one-year training program after our family medicine training. A few of us are emergency medicine physicians, pediatricians, orthopedic surgeons or physiatrists (physicians who specialize in physical medicine and rehabilitation). We usually take a team approach, working with many other health professionals like physiotherapists, athletic therapists, chiropractors, kinesiologists and dietitians. This way, patients get access to the widest range of treatments and expertise.

“Some patients we only see two or three times to diagnosis their situation and help them with an appropriate treatment and exercise plan. We have a longer-term relationship with other patients – and their families – because they come back for other injuries and we become their go-to physician for musculoskeletal issues. We might treat patients with osteoarthritis or another chronic issue for years. When we’re the team physician for a local, varsity or professional sports team, we effectively become their sport medicine doctors and family physician in one, looking after their sports injuries, and other health needs which will often include mental health issues. As the physician for athletes on a national team, we work with a support team to take care of the whole person, including issues around sleep, nutrition, periodized training, and travel.

“Sport and exercise medicine is a fast-growing, evidence-based field with many new treatments that are cutting edge and early in research phases. But there really is no quick fix, no magic solution, regardless of what you might see on TV or social media. If you’re curious about a topical cream, supplement, performance-enhancing drug, or electrical stimulation device, ask your family doctor or a sport medicine physician. Many of these things don’t have scientific evidence behind them and can even be harmful. When it comes to your health, get your information from a qualified professional. Sport and exercise medicine physicians will work with your family physician or other specialists to improve your pain and get you back to exercise!”


Practising doctors: 253

Urologists diagnose and treat diseases of the urinary tract in men and women, and the reproductive tract in men. In some cases, they may perform surgery. For example, they may remove cancer or open up a blockage in the urinary tract.


Vascular surgery

Practising doctors: 90

Vascular surgeons specialize in treating conditions that affect blood vessels including arteries, veins and the lymphatic system, such as aortic aneurysms, stroke, poor leg circulation and varicose veins. They also perform procedures including minimal invasive balloon angioplasty, stenting of arteries and veins, and reconstructive vascular surgery.