Common Types of Doctors and What They Do

Allergist/Immunologist

A doctor who specializes in treating allergies and immunologic disorders is called an allergist/immunologist, though sometimes this specialty will simply be referred to as an allergist or immunologist. These doctors treat people with allergies and asthma as well as people with primary immunodeficiency disease. 

Allergists/immunologists complete three years of training in internal medicine or pediatrics and an additional two-year fellowship in an allergy/immunology training program.

Anesthesiologist

Anesthesiologists are trained to manage patient pain and vital signs during surgery. They also often manage medical emergencies in the hospital, such as cardiac arrest and sudden breathing problems.

Aspiring anesthesiologists must attend medical school followed by a residency program for anesthesiology. There are numerous subspecialties of anesthesiology they may attend fellowships for, including anesthesia for patients with chronic pain or for patients in the ICU.

Cardiologist

Cardiologists focus on treatment of the heart and its blood vessels. This can include the management of heart failure, cardiovascular disease, and post-operative care.

Training to become a cardiologist is fairly extensive. After completing three years of internal medicine residency, aspiring cardiologists need to attend several more years of fellowship training.

Dermatologist

Dermatologists diagnose and treat conditions that affect the hair, skin, and nails. This may include treating rashes or acne, diagnosing melanoma (skin cancer), and much more.

In addition to this, dermatoligists also perform many aesthetic procedures that are paid for out of pocket rather than by insurance. Such procedures include Botox injections, laser skin treatments, and more.

After medical school, dermatologists must attend dermatology residency. Fellowships are not required, but some dermatologists may attend them if they choose to subspecialize in a particular aspect of dermatology.

Dermatology is a very competitive field for physicians. One reason for this is that dermatologists are very well compensated. Typically, only the top medical students are accepted into dermatology residency programs.

Endocrinologist

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 or thyroid disease are often treated by an endocrinologist.

Like other internal medicine physicians, endocrinologists attend medical school followed by an internal medicine residency. They are then required to attend fellowship training for endocrinology.

Family Physician

Family practice physicians are primary care providers who see patients of all ages and provide basic care for a variety of common ailments. They are usually the first to recognize major health problems, order diagnostic tests, and refer patients to specialists when needed.

After attending medical school, family medicine physicians attend a family medicine residency program for three to five years. During this time, they will receive hands-on training in pediatric care, emergency medicine, and other areas of general medicine.

Gastroenterologist

Gastroenterologists treat the functions and diseases of the digestive system.This field attracts physicians who enjoy doing procedures, but who also like seeing patients in an outpatient setting.

Gastroenterology is another subspecialty of internal medicine. At minimum, gastroenterologists attend medical school followed by an internal medicine residency. From there, they need to attend fellowship training for gastroenterology.

Geneticist

A geneticist is a doctor who evaluates and treats people with inherited disorders such as Huntington's disease or cystic fibrosis.

Geneticists may treat patients directly or work in a laboratory setting to help diagnose patients. Some geneticists also work as genetic counselors to help counsel patients who have been diagnosed with a genetic condition. Geneticists often also conduct research into clinical genetics and patient care. 

Geneticists have medical degrees and have completed at least a year of residency in a primary specialty and two years of medical genetics training. They may further specialize in pediatrics, internal medicine, maternal-fetal medicine, or reproductive endocrinology and infertility. They are certified by the American Board of Medical Genetics and Genomics. 

Hematologist

Hematologists specialize in diseases of the blood, including cancers of the blood such as leukemia and lymphoma. Hematologists also treat non-cancerous conditions like hemophilia and anemia. Hematologists work directly with patients, while hematopathologists help diagnose blood-related diseases in a laboratory.

Hematologists complete four years of medical school followed by a three-year residency in a specialty such as pediatrics or internal medicine. They are also required to complete a two- to four-year fellowship in a subspecialty such as pediatric hematology/oncology or pathology. 

Hospice and Palliative Medicine Specialist

A hospice and palliative medicine specialist helps patients who have serious illnesses or are at the end of life. This type of doctor does not focus on treating or curing the illness itself but instead helps manage pain and improve quality of life.

A palliative medicine specialist may work in a hospital, in a hospice center, in an outpatient setting, or in other facilities that provide end-of-life care or treat and support people with serious illnesses.

After finishing medical school, a person training to be a hospice and palliative medicine specialist completes a three- to seven-year residency program in a specialty such as family medicine, pediatrics, or psychiatry. After residency, they must complete a one-year specialized training fellowship.

Infectious Disease Physician

Infectious disease physicians deal with infections that are hard to diagnose or treat. They also treat serious infections such as the swine flu, bird flu, HIV/AIDS, and other infectious diseases.

After medical school, infectious disease physicians must attend an internal medicine residency followed by fellowship training for infectious diseases.

Internal Medicine Physician

General internists provide primary care to adult patients.

Internists usually have more hospital-based training than family practitioners. They may have an office-based practice or work as a hospitalist primarily seeing patients in the hospital.

These physicians attend medical school followed by an internal medicine residency.

Internists may then choose to pursue a fellowship to subspecialize in a variety of other areas, like endocrinology (hormone-related conditions) or cardiology (heart-related issues).

Nephrologist

Nephrologists treat kidney disease and prescribe dialysis for those experiencing kidney failure.

After medical school, these physicians attend an internal medicine residency program. They are then required to attend fellowship training for nephrology.

Neurologist

Neurologists are doctors who take care of patients with medical conditions that affect the brain, spine, or nerves.

They see patients who have complex medical disorders such as Parkinson's disease, multiple sclerosis, and neuropathy. Neurologists also take care of patients who have common problems such as migraine headaches and dizziness.

Like other physicians, neurologists must attend medical school then a residency for neurology. From there, they may pursue fellowship training for a subspecialty, such as pediatric neurology or vascular neurology (related to blood vessels in the brain).

Obstetrician/Gynecologist (OB/GYN)

A gynecologist is a doctor who specializes in female reproductive health, including menopause and hormone problems. An obstetrician provides care for people who are pregnant. Obstetricians also are trained to deliver babies.

Often, these specialities are combined, in which case the physician is referred to as an OB/GYN.

At minimum, OB/GYNs must attend medical school followed by a residency program. Once their residency is complete, some continue their training with a fellowship for a subspecialty. Gynecological oncology—a field that deals with cancer of the female reproductive organs—is just one example.

Oncologist

Oncology is a subspecialty of internal medicine that has three main areas: medical, surgical, or radiation oncology.

Oncologists take care of patients who have cancer by treating the disease itself, as well as the symptoms it causes.

Often, oncologists take part in clinical trials using new and experimental treatments for cancers that are otherwise incurable.

Oncologists attend medical school followed by an oncology residency. There are also fellowships for subspecialties of oncology, like pediatric oncology (children's cancer) and radiation oncology (radiation treatment for cancer).

Ophthalmologist

Ophthalmologists are medical doctors who treat diseases or disorders of the eyes, such as cataracts and glaucoma.

Vision correction that cannot be handled by an optometrist may be treated by an ophthalmologist. When necessary, ophthalmologists will also perform eye surgery.

Ophthalmologists attend medical school followed by a residency for ophthalmology. They are not required to take a fellowship, although many choose to attend fellowship training for specific eye diseases or surgical procedures.

Orthopedist

An orthopedist or orthopedic surgeon is a doctor who specializes in conditions of the musculoskeletal system, including the bones, muscles, joints, and connective tissues. These physicians see patients with injuries such as sprains, joint injuries, and broken bones. They also specialize in chronic conditions like osteoarthritis, tendonitis, dysplasia, and osteoporosis.

Orthopedists diagnose and treat conditions of the musculoskeletal system, monitor patient rehabilitation, and perform surgery when necessary.

Orthopedic surgeons complete a five-year residency program with the option to complete fellowship training. 

Osteopath

An osteopath is a doctor who specializes in treating the whole person. These physicians typically practice primary care medicine such as pediatrics or internal medicine. They use musculoskeletal or cranial manipulation to restore balance in body systems such as the respiratory, digestive, or nervous systems.

An osteopath completes four years of basic medical school followed by three to eight years of specialty internships, residencies, and fellowships. 

Otolaryngologist

Otolaryngologists are more commonly referred to as ENTs, or ear/nose/throat doctors.

Otolaryngology is a field that entails a combination of surgical skills and office-based medicine and treatment. They are required to attend medical school in addition to residency for otolaryngology.

ENTs handle a lot of issues, including sinus problems, allergies, head and neck cancers, and more. Because of this, many ENTs attend fellowships for a subspecialty of otolaryngology, such as rhinology, which focuses on issues related to the nose and sinuses.

Pathologist

Pathologists specialize in investigating the cause and effect of disease and injury. These physicians are trained to evaluate tissue, blood, and body fluids to help diagnose and treat illnesses. Some pathologists also examine bodies to help find the cause of death.

Clinical pathologists work with blood and other body fluids in a laboratory setting, while anatomical pathologists may examine whole organs and tissues during an autopsy. 

Pathologists are usually trained in both clinical and anatomical pathology and may specialize in areas such as chemical pathology (including toxicology), hematology (the study of diseases of the blood), or forensic pathology. 

In the United States, pathologists complete medical school followed by three years of residency training. They are certified by the American Board of Pathology. 

Pediatrician

Pediatricians take care of patients from infancy through age 18 or, in some cases, age 21.

Pediatricians provide primary health care to children, including vaccinations, general health checkups, school physicals, and treatment of issues like coughs, colds, and stomach flu.

If a patient has a more serious illness, their pediatrician may refer them to a pediatric subspecialist (e.g., a pediatric orthopedist is a doctor who specializes in treating young patients with bone and muscle concerns).

After they graduate from medical school, pediatricians spend at least three years in a residency program that is focused on pediatric medicine. If they choose to study a pediatric subspecialty, they will then attend a fellowship for that subspecialty.

Physician Executive

Some physicians do not practice medicine. Instead, they take leading roles in health care policy, pharmaceutical research, or health insurance companies.

Non-clinical doctors generally are required to have completed medical school and residency. They must also maintain a medical license.

Plastic Surgeon

Plastic surgeons are surgeons who specialize in changing a person's appearance. These doctors may perform plastic surgery for cosmetic reasons, such as changing the appearance of a person's nose or removing skin under the neck, or because a person requires reconstruction following injury or illness. 

A plastic surgeon can help improve a person's well-being and ability to function as well as their outward appearance. For example, treating a cleft palate with plastic surgery can improve a person's ability to breathe or speak. Plastic surgery can also help improve the appearance of burns or scars or reduce the signs of aging. 

Plastic surgeons complete at least five years of graduate medical training including three years of general surgery and two years of plastic surgery.

Podiatrist

A podiatrist is a doctor who treats problems with the foot, ankle, and lower leg, such as osteoarthritis in the ankle, diabetic foot disorders, foot and ankle injuries, skin and nail conditions of the foot, and foot deformities like flat feet and hammertoe.

Podiatrists must complete four years of education in a specialized podiatric medical school. They must also complete a two-year residency that provides experience in additional areas such as surgery, ER, and pediatrics. 

Pulmonologist

Pulmonologists treat the cardio-pulmonary system, which consists of the heart, lungs, and organs involved in the respiratory process.

In addition, pulmonologists may work in office settings to treat patients with breathing disorders, severe allergies, lung problems, and other respiratory diseases. They may also treat patients with pulmonary disease who are in the intensive care unit (ICU).

Aspiring pulmonologists attend medical school followed by an internal medicine residency. They then attend fellowship training for pulmonology.

Psychiatrist

A psychiatrist specializes in mental health. They treat emotional and behavioral problems through a combination of psychotherapy, psychoanalysis, medication, and hospitalization.Their work may be office-based, hospital-based, or a combination of the two.

After medical school and residency for psychiatry, some psychiatrists attend fellowships for a subspecialty. There are a number of different specialty areas within psychiatry, including child and adolescent psychiatry, addiction medicine, or eating disorders.

Radiologist

A radiologist is a physician who is trained in viewing and interpreting diagnostic tests.

Often, the treating physician must interpret test results as well. The radiologist's analysis can offer additional information or advice for further testing.

Before a radiologist is licensed, they must attend medical school and a residency for radiology. From there, they may choose to attend fellowship training for a subspecialty of radiology that is focused on a specific aspect of radiology or area of the body.

Rheumatologist

Rheumatologists treat rheumatic diseases, or autoimmune and inflammatory diseases of the musculoskeletal system. The most common condition a rheumatologist treats is arthritis including osteoarthritis (wear and tear arthritis) and rheumatoid arthritis (an autoimmune condition). They also treat other autoimmune diseases such as lupus and scleroderma. A rheumatologist may also treat chronic back pain, fibromyalgia, osteoporosis, and related conditions.

After medical school, rheumatologists complete a three-year basic internal medicine residency followed by a rheumatology fellowship. Rheumatologists are certified by the American Board of Internal Medicine.

Sleep Medicine Specialist

A sleep medicine specialist treats sleep disorders such as sleep apnea, restless legs syndrome, and insomnia. 

Sleep medicine is considered multidisciplinary, which means there is a broad range of specialties within it. For example, a psychiatrist who specializes in sleep disorders may treat people with insomnia while a pediatrician may work with children who sleep talk, sleepwalk, or have night terrors. 

Sleep specialists first complete a residency in another specialty such as internal medicine, pediatrics, family medicine, or neurology. A one-year fellowship is required after the residency is completed. Internists complete a three-year fellowship in pulmonary/critical care before completing sleep medicine training.

Surgeon

Surgeons spend time planning a surgical procedure, performing surgery in the operating room, and then following up afterwards to identify any complications and confirm that the procedure was a success.

Surgeons can be trained in general surgery or in more specialized areas of surgery, such as hand surgery, pediatric surgery, or vascular surgery (related to blood flow problems).

The training to become a surgeon is typically several years longer than training for a primary care doctor. Following medical school, general surgeons must attend a residency program for three to five years. Once they are board-certified, they will attend a fellowship or internship in a surgical department.

Urologist

A urologist is a doctor who treats diseases of the male and female urinary tract, including conditions of the bladder and kidneys. Urologists also treat conditions of the male reproductive system. 

After medical school, a person training to be a urologist must complete five years of postgraduate medical training including one year of general surgery and four years of clinical urology. 

Summary

Being familiar with the different types of physician specialties helps you know who to call when you need medical care. It also helps those planning a career in medicine, as they think through what they'd like to do on a day-by-day basis.

The Association of American Medical Colleges maintains a database of more than 135 specialties and subspecialties that you can explore. It will help you to understand more about the type of provider you need—or want to become.