A specialty (or speciality) in medicine is a branch of medical science. After completing medical school, physicians or surgeons usually further their medical education in a specific specialty of medicine by completing a multiple year residency to become a medical specialist.
History of medical specialization 
To a certain extent, medical practitioners have always been specialized. According to Galen, specialization was common among Roman doctors. The particular system of modern medical specialities evolved gradually during the 19th century. Informal social recognition of medical specialization evolved before the formal legal system. The particular subdivision of the practice of medicine into various specialities varies from country to country, and is somewhat arbitrary.
Classification of medical specialization 
Medical specialties can be classified along several axes. These are:
- Surgical or internal medicine
- Age range of patients
- Diagnostic or therapeutic
- Organ-based or technique-based
Throughout history, the most important has been the division into surgical and internal medicine specialties. The surgical specialties are the specialties in which an important part of diagnosis and treatment is achieved through major surgical techniques. The internal medicine specialties are the specialties in which the main diagnosis and treatment is never major surgery. Anesthesiology is classified as a surgical discipline, since it is vital in the surgical process, though anesthesiologists never perform major surgery themselves.
Many specialties are organ-based. Many symptoms and diseases come from a particular organ. Others are based mainly around a set of techniques, such as radiology, which was originally based around X-rays.
The age range of patients seen by any given specialist can be quite variable. Paediatricians handle most complaints and diseases in children that do not require surgery, and there are several subspecialties (formally or informally) in paediatrics that mimic the organ-based specialties in adults. Paediatric surgery may or may not be a separate specialty that handles some kinds of surgical complaints in children.
A further subdivision is the diagnostic versus therapeutic specialties. While the diagnostic process is of great importance in all specialties, some specialists perform mainly or only diagnostic examinations, such as pathology, clinical neurophysiology, and radiology. This line is becoming somewhat blurred with interventional radiology, an evolving field that uses image expertise to perform minimally invasive procedures.
Specialties that are common world-wide 
|Specialty||Can be subspecialty of||Diagnostic (D) or therapeutic (T) specialty||Surgical (S) or internal medicine specialty (I)||Age range of patients||Organ-based (O) or technique-based (T)|
|Allergy and Immunology||Paediatrics or Internal medicine||Both||I||All||O|
|Cardiothoracic surgery||General surgery||T||S||Adults||O|
|Child and adolescent psychiatry and psychotherapy||None||T||I||Paediatric||O|
|Emergency Medicine||None||T & D||I||All||O & T|
|Gynaecology and obstetrics||None||T||S||All||O|
|Health Informatics||None||T & D||Neither||All||Multidisciplinary|
|Infectious diseases||Internal medicine||T||I||Variable||Neither|
|Vascular medicine||Internal medicine||T||I||Adults||O|
|Occupational medicine||None||T||I||Working age||Multidisciplinary|
|Oral and Maxillofacial Surgery||Several||T||S||All||O|
|Paediatric endocrinology and diabetes||Paediatrics||T||I||Paediatric||O|
|Paediatric gastroenterology, hepatology and nutrition||Paediatrics||T||I||Paediatric||O|
|Paediatric haematology and oncology||Paediatrics||T||I||Paediatric||O|
|Paediatric infectious diseases||Paediatrics||T||I||Paediatric||O|
|Paediatric respiratory medicine||Paediatrics||T||I||Paediatric||O|
|Paediatric surgery||General Surgery||T||S||Paediatric||O|
|Physical and Rehabilitation Medicine||None||T||I||Adults||Multidisciplinary|
|Plastic, Reconstructive and Aesthetic Surgery||General surgery||T||S||All||O|
|Vascular surgery||General surgery||T||S||All||O|
List of specialties recognized in the European Union and European Economic Area 
The European Union publishes a list of specialties recognized in the European Union, and by extension, the European Economic Area. Note that there is substantial overlap between some of the specialties and it is likely that for example "Clinical radiology" and "Radiology" refer to a large degree to the same pattern of practice across Europe.
|Anaesthetics||Clinical chemistry||Tropical medicine|
|General surgery||Clinical biology||Child psychiatry|
|Obstetrics and gynecology||Plastic surgery||Nephrology|
|Internal medicine||Thoracic surgery||Infectious diseases|
|**Ophthalmology||Paediatric surgery||Public health and Preventive Medicine|
|Orthopaedics||General hematology||Nuclear medicine|
|Pathology||Endocrinology||Accident and emergency medicine|
|Neurology||Physical medicine and rehabilitation||Clinical neurophysiology|
|Clinical radiology||Neuro-psychiatry||Dental, oral and maxillo-facial surgery|
|Laboratory medicine||Dermatology||Podiatric Medicine|
List of North American medical specialities and others 
||The examples and perspective in this article may not represent a worldwide view of the subject. (January 2010)|
In this table, as in many healthcare arenas, medical specialties are organized into the following groups:
- Surgical specialties focus on manually operative and instrumental techniques to treat disease.
- Medical specialties that focus on the diagnosis and non-surgical treatment of disease.
- Diagnostic specialties focus more purely on diagnosis of disorders.
|Allergy and Immunology||Allergic reactions, asthma, and the immune system|
|Anesthesiology||AN, PAN||Surgery||Pediatrics, Pain management, Intensive Care, Critical Care, Obstetrics and gynaecology, Cardiothoracic anesthesiology, Trauma Care, Pre- and Post-Operative Assessment and Care, Generalist (covers all the sub-specialties)||Anesthesia|
|Cardiology||Medicine||Disease of the cardiovascular system|
|Cardiovascular surgery||Surgery||The operation of heart and major blood vessels of the chest.|
|Clinical laboratory sciences||Diagnostic||
||Application of diagnostic techniques in medical laboratories such as assays, microscope analysis.|
|Dermatology||D, DS||Medicine||Dermatopathology, Mohs Surgery||Skin and its appendages (hair, nails, sweat glands etc.).|
|Dietetics||Food and nutrition|
||The initial management of emergent medical conditions, often in hospital emergency departments or the field.|
|Endocrinology||Medicine||The endocrine system (i.e., endocrine glands and hormones) and its diseases, including diabetes and thyroid diseases.|
||Continuing, comprehensive healthcare for the individual and family, integrating the biological, clinical and behavioral sciences to treat patients of all ages, sexes, organ systems, and diseases.|
|Gastroenterology||GI||Medicine||The alimentary tract|
|Gynecology||Female reproductive health|
|Hepatology||Medicine||The liver and biliary tract, usually a part of gastroenterology.|
|Infectious disease||ID||Medicine||Diseases caused by biological agents|
|Intensive care medicine||Medicine||Life support and management of critically ill patients, often in an ICU.|
|Medical research||Anatomy, Biochemistry, Embryology, Genetics, Pharmacology, Toxicology|
|Neurology||N||Medicine||Diseases involving the central, peripheral, and autonomic nervous systems|
|Neurosurgery||NS||Surgery||Disease of the central nervous system, peripheral nervous system, and spinal column.|
|Obstetrics and gynecology||OB/GYN||Surgery|
|Oncology||ON||Medicine||Cancer and other malignant diseases, often grouped with hematology.|
|Ophthalmology||OPH||Surgery||Retina, Cornea||Diseases of the visual pathways, including the eyes, brain, etc.|
|Oral and maxillofacial surgery||Maxfacs, OMS||Surgery||
||Disease of the head, neck, face, jaws and the hard and soft tissues of the oral and maxillofacial region.|
|Orthopedic surgery||ORS||Surgery||hand surgery, surgical sports medicine, adult reconstruction, spine surgery, foot and ankle, musculoskeletal oncology, orthopaedic trauma surgery, pediatric orthopedic surgery||Injury and disease of the musculoskeletal system.|
|Otorhinolaryngology, or ENT||ORL, ENT||Surgery||Head and neck, facial cosmetic surgery, Neurotology, Laryngology||Treatment of ear, nose, and throat disorders. The term head and neck surgery defines a closely related specialty that is concerned mainly with the surgical management of cancer of the same anatomical structures.|
|Palliative care||PLM||Medicine||A relatively modern branch of clinical medicine that deals with pain and symptom relief and emotional support in patients with terminal illnesses including cancer and heart failure.|
|Pathology||PTH||Diagnostic||Understanding disease through examination of molecules, cells, tissues and organs. The term encompasses both the medical specialty that uses tissues and body fluids to obtain clinically useful information and the related scientific study of disease processes.|
|Pediatrics||PD||Medicine||Children. Like internal medicine, pediatrics has many subspecialities for specific age ranges, organ systems, disease classes, and sites of care delivery. Most subspecialities of adult medicine have a pediatric equivalent such as pediatric cardiology, pediatric endocrinology, pediatric gastroenterology, pediatric hematology, pediatric oncology, pediatric ophthalmology, and neonatology.||deals with the medical care of infants, children, and adolescents (from newborn to age 16-21, depending on the country).|
|Pediatric surgery||Surgery||Treats a wide variety of thoracic and abdominal (and sometimes urologic) diseases of childhood.|
|Physical medicine and rehabilitation Or Physiatry||PM&R||Medicine||Concerned with functional improvement after injury, illness, or congenital disorders.|
||Elective cosmetic surgery as well as reconstructive surgery after traumatic or operative mutilation.|
||Elective podiatric surgery of the foot and ankle, lower limb diabetic wound and salvation, peripheral vascular disease limb preservation, lower limb mononeuropathy conditions.|
|Proctology||PRO||Medicine||(or Colorectal Surgery) Treats disease in the rectum, anus, and colon.|
||The bio-psycho-social study of the etiology, diagnosis, treatment and prevention of cognitive, perceptual, emotional and behavioral disorders. Related non-medical fields include psychotherapy and clinical psychology.|
|Pulmonology||Medicine||The lungs and respiratory system. Pulmonology is generally considered a branch of internal medicine, although it is closely related to intensive care medicine when dealing with patients requiring mechanical ventilation.|
|Radiology||R, DR||Diagnostic and Therapeutic||
||The use of expertise in radiation in the context of medical imaging for diagnosis or image guided minimally invasive therapy. X-rays, etc.|
|Rheumatology||RHU||Medicine||Autoimmune and inflammatory diseases of the joints and other organ systems, such as arthritis and other rheumatic diseases.|
|Stomatology||Dentistry||Diseases of the mouth|
|Surgical oncology||SO||Surgery||Curative and palliative surgical approaches to cancer treatment.|
|Thoracic surgery||TS||Surgery||Surgery of the organs of the thoracic cavity: the heart, lungs, and great vessels.|
|Transplant surgery||TTS||Surgery||Transplantation of organs from one body to another|
|Urgent Care Medicine||UCM||Medicine||Immediate medical care offering outpatient care for the treatment of acute and chronic illness and injury|
|Urology||U||Surgery||Urinary tracts of males and females, and the male reproductive system. It is often practiced together with andrology ("men's health").|
|Vascular surgery||VS||Surgery||The peripheral blood vessels – those outside of the chest (usually operated on by cardiovascular surgeons) and of the central nervous system (treated by neurosurgery)|
Future medical specialties 
|This section does not cite any references or sources. (January 2013)|
Due to the large decline in men's use of healthcare services and facilities, there may be a future in creating a specialty dedicated exclusively to men's health and well being. It would be a counterpart to gynecology and would be most aptly named andrology.
Physician compensation 
The mean annual salary of a medical specialist is $175,011 in the US, and $272,000 for surgeons. However, because of commodity inflation, increasing negligent costs, steep price rise of rental, the annual salary range of a medical specialist varies and is not rising as fast as other professional pay. Oftentimes, especially in the United States, physicians practice in groups of specialists within a particular medical specialty. These practice groups are often formed to help reach economies of scales in rental, insurance and staff costs as well as other benefits of practicing with other professionals and are typically governed by various legal documents.
The table below details the average range of salaries for physicians of selected specialties as of July 2010. Also given in the average number of hours worked per week for full-time physicians (numbers are from 2003).
|Specialty||Median salary (USD)||Average hours
|Average salary/hour (USD)|
|Anesthesiology||331,000 to $423,507||61|
|Dermatology||313,100 to $480,088||45.5||103|
|Emergency medicine||239,000 to $316,296||46||87|
|Cardiac Surgery||218,684 to $500,000||55|
|Family practice||175,000 to $220,196||52.5||58|
|Internal medicine||184,200 to $231,691||57||58|
|Neurology||213,000 to $301,327||55.5||93|
|Obstetrics and Gynecology||251,500 to $326,924||61||83|
|Ophthalmology||150,000 to $351,000||47|
|Orthopedic surgery||397,879 to $600,000||58|
|Otolaryngology||191,000 to $393,000||53.5|
|Pathology||239,000 to $331,842||45.5|
|Pediatrics||160,111 to $228,750||54||69|
|Psychiatry||173,800 to $248,198||48||72|
|Radiology (diagnostic)||377,300 to $478,000||58|
|Surgery (general)||284,642 to $383,333||60|
|Urology||331,192 to $443,518||60.5|
|Neurological surgery||350,000 to $705,000||132|
|Plastic surgery||265,000 to $500,000||114|
|Gastroenterology||251,026 to $396,450||93|
|Pulmonology||165,000 to $365,875||72|
Specialties by country 
Australia and New Zealand 
Specialty training in Australia and New Zealand is overseen by the specialty colleges:
Specialty training in Canada is overseen by the Royal College of Physicians and Surgeons of Canada
Specialty training in India is overseen by the Medical Council of India, which is responsible for recognition of post graduate training and by the National Board of Examinations. And education of Ayurveda in overseen by Central Council of Indian Medicine (CCIM), the council conducts u.g and p.g courses all over India, while Central Council of Homoeopathy does the same in the field of Homeopathy.
United States 
There are three agencies or organizations in the United States that collectively oversee physician board certification of MD and DO physicians in the United States in the 26 approved medical specialties recognized in the country. These organizations are the American Board of Medical Specialties (ABMS) and the American Medical Association (AMA); the American Osteopathic Association Bureau of Osteopathic Specialists (AOABOS) and the American Osteopathic Association; the American Board of Physician Specialties (ABPS) and the American Association of Physician Specialists (AAPS). Each of these agencies and their associated national medical organization functions as its various specialty academies, colleges and societies.
|Certifying Board||National Organization||Physician Type|
|ABMS||AMA||MD and DO|
|ABPS||AAPS||MD and DO|
All boards of certification now require that medical practitioners demonstrate, by examination, continuing mastery of the core knowledge and skills for a chosen specialty. Recertification varies by particular specialty between every seven and every ten years.
Other uses 
In the U.S. Army, the term "medical specialist" refers to occupational therapists, physical therapists, dietitians and physician assistants, also known as allied health professionals. Also included in the term "medical specialist", but not in the term "allied health professional" are EMT/combat medics.
A survey of physicians in the United States came to the result that dermatologists are most satisfied with their choice of specialty followed by radiologists, oncologists, plastic surgeons, and gastroenterologists. In contrast, primary care physicians were the least satisfied, followed by nephrologists, obstetricians/gynecologists, and pulmonologists.
|Specialty||Overall satisfaction||Feeling of enough compensation||Would have chosen same specialty again|
|Infectious disease/HIV physician||66%||54%||73%|
|Emergency medicine physician||63%||65%||56%|
|Primary care physician||54%||48%||43%|
See also 
- Interdisciplinary sub-specialties of medicine, including
- Occupational medicine – branch of clinical medicine that provides health advice to organizations and individuals concerning work-related health and safety issues and standards. See occupational safety and health.
- Disaster medicine – branch of medicine that provides healthcare services to disaster survivors; guides medically related disaster preparation, disaster planning, disaster response and disaster recovery throughout the disaster life cycle and serves as a liaison between and partner to the medical contingency planner, the emergency management professional, the incident command system, government and policy makers.
- Preventive medicine – part of medicine engaged with preventing disease rather than curing it. It can be contrasted not only with curative medicine, but also with public health methods (which work at the level of population health rather than individual health).
- Medical genetics – the application of genetics to medicine. Medical genetics is a broad and varied field. It encompasses many different individual fields, including clinical genetics, biochemical genetics, cytogenetics, molecular genetics, the genetics of common diseases (such as neural tube defects), and genetic counseling.
- Specialty Registrar
- Federation of National Specialty Societies of Canada
- Society of General Internal Medicine
- Weisz G (Fall, 2003). "The Emergence of Medical Specialization in the Nineteenth Century". Bull Hist Med 77 (3): 536–574. PMID 14523260.
- "Directive 2005/36/EC of the European Parliament and of the Council of 7 September 2005 on the recognition of professional qualifications". European Parliament and Council. Retrieved 19 April 2011.
- Regeringen.se – new grouping of the medical specialties
- ibmdllc.com -Physician income not rising as fast as other professional pay[dead link]
- "Physician Separation Issues". The National Law Review. Baker & Hostetler LLP. 2011-11-21. Retrieved 2012-01-13.
- Physician Compensation Survey [special feature]. Modern Healthcare. July 19, 2010: 20-26. 
- Physician work hours (2003) Medfriends.org. Accessed 15 December 2010.
- Leigh JP, Tancredi D, Jerant A, Kravitz RL (October 2010). "Physician wages across specialties: informing the physician reimbursement debate". Arch. Intern. Med. 170 (19): 1728–34. doi:10.1001/archinternmed.2010.350. PMID 20975019. 
- Medscape Physician Compensation Report: 2011