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.
Allergy and clinical immunology
Practising doctors: 137
Allergists/immunologists specialize in the diagnosis, treatment and management of allergies, asthma and immunologic disorders.
Anesthesia
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.
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.
Cardiology
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.
Dermatology
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.
Endocrinology
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.
Gastroenterology
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.
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.
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.
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.
Nephrology
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.
Neurology
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.
Neuroradiology
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.
Neurosurgery
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.
Opthalmology
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.
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.
Pediatrics
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.
Psychiatry
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.
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.
Rheumatology
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.
Urology
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.