Types of Doctors

The Most Common Physician Specialties

Physicians are categorized by a variety of factors, including medical specialty and patient population. If you're considering joining the ranks of the nearly one million physicians already practicing in the United States, read on to learn more about the different types of doctors you could become.

Family Physician

Team of doctors discussing in hospital, smiling
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Family medicine is one of the specialties of primary care physicians. Family practice physicians see patients of all ages and provide basic care for a variety of more common ailments.

Internal Medicine Physician

Internists also can provide primary care, or they can sub-specialize in a variety of other areas, such as gastroenterology or endocrinology, to name a few of many options.

Internists usually have more hospital-based training than family practitioners, and internists do not typically see children under the age of 18.


A relatively new specialty (the term was introduced in 1996), hospitalists only see patients in the hospital. Most hospitalists are physicians who trained in internal medicine but prefer hospital work over more clinic-based primary care. Some hospitalists may be trained in family practice, but that's not as common.


Surgeons can be trained in general surgery or more specialized types, such as orthopedic surgery, neurosurgery, or cardiac surgery. Surgeons spend a great deal of time in the operating room of a hospital or outpatient surgery center.

The training to become a surgeon is typically several years longer than primary care and some medical sub-specialties.


Cardiology is one of many sub-specialties of internal medicine. Cardiologists focus on treatment of the heart and blood vessels of the cardiovascular system. There are many different types of cardiologists, focusing on different aspects of the field.

Training to become a cardiologist is fairly extensive, as several years of fellowship are required after completing three years of internal medicine residency. All together, a minimum of six years of residency and fellowship after medical school is typical for cardiologists in training.


Dermatology is one of the most competitive fields for physicians. Typically, only the very top medical students are accepted into dermatology residency programs. This is because dermatologists are very well compensated (due to aesthetic and cash-pay elective procedures such as Botox, lasers, and more). Plus, the quality of life is excellent, with little to no on-call time required due to the nature of the work.


A sub-specialty of internal medicine, endocrinologists treat the endocrine system—the glands that produce and secrete hormones that control and regulate nearly all of the body's functions. People with diabetes are often treated by an endocrinologist, as are patients with various thyroid issues.


A sub-specialty of internal medicine, gastroenterologists treat the digestive system. This field attracts physicians who enjoy doing procedures, but who also like seeing patients in an outpatient setting as well.

Infectious Disease Physician

Infectious disease physicians deal with swine flu, bird flu, as well as HIV/AIDS, among other communicable diseases. A sub-specialty of internal medicine, infectious disease physicians may practice some primary care internal medicine in addition to their infectious disease patients, depending on the needs of the community or employer. But generally, patients who are referred to an infectious disease doctors have infections that have not been identified or are hard to treat.


Nephrologists treat kidney disease and prescribe dialysis for those experiencing kidney failure. These physicians study internal medicine and then sub-specialize in nephrology, which requires an additional two to three years of fellowship training. 


Ophthalmologists are medical doctors who treat diseases or disorders of the eyes and perform eye surgery. Vision correction that cannot be handled by an optometrist may be treated by an ophthalmologist.

Obstetrician/Gynecologist (OB/GYN)

An OB/GYN is a doctor who specializes in women's reproductive health. These doctors provide women with preventive care, manage pregnancy, labor, and delivery, and diagnose and treat diseases of the reproductive organs. They also specialize in women’s health issues like menopause, hormone problems, contraception, and infertility.


Otolaryngologists, also known as otorhinolaryngologists, are sometimes more commonly referred to as ENTs, which stands for "ear, nose, and throat." Otolaryngology is another field that entails a combination of surgical skills and office-based medicine and treatment.

ENTs cover a lot of issues including sinus problems, allergies, head and neck cancers, and more. As a result, many physicians sub-specialize in a specific area of otolaryngology. However, the current demand is for more general otolaryngologists as opposed to sub-specialized ones.


You must really love kids to be a pediatrician. These physicians only care for younger patients, from infancy through age 18, or sometimes as high as age 21.

Pediatricians provide primary health care to children including immunizations, well-baby checks, school physicals, and treatment of coughs and colds, among many other things. More seriously ill or complicated patients may be referred to a pediatric sub-specialist for more specialized treatment.


Pulmonologists treat the cardio-pulmonary system, which consists of all the organs, including the lungs and heart, that work together to help a person breathe. They often study critical care medicine in conjunction with pulmonary disease. As a result, they may serve as intensivists, physicians who cover the intensive care unit, in addition to also seeing patients in an office setting to treat breathing disorders, severe allergies, lung problems, and other diseases.


A psychiatrist treats the mental health and well-being of the patient through a combination of personal counseling (psychotherapy), psychoanalysis, hospitalization, and medication. Psychiatrists may be office-based, hospital-based, or a combination of the two.

There are a number of different specialty areas within psychiatry: For instance, some psychiatrists may focus on child and adolescent psychiatry, addiction medicine, or on treating older people.

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View Article Sources
  • Federation of State Medical Boards. A Census of Actively Licensed Physicians in the United States, 2016. https://www.fsmb.org/globalassets/advocacy/publications/2016census.pdf