What Do Different Types of Physicians Do?

Different types of physicians practice different types of medicine. Everyone knows that a family physician isn't trained to perform a heart transplant. However, what exactly do different types of physicians do, and what conditions do they most commonly treat?

Physician talking to mother and daughter in exam room
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Let's take a look at several different specialties and subspecialties. We'll first start with a look at physicians who specialize in primary care and then we'll look at some other fields. A lot of this information is derived from association websites that represent these physicians. When prudent, links will be provided to learn more about these fields.

The purpose of this article is not to provide comprehensive coverage. Instead, this article should serve to empower you as a patient and help you cut through the jargon that populates medicine. By understanding what some of the most common specialists and subspecialists do, you can better understand the care you receive and the roles and responsibilities of the physician who provides you treatment.

Primary Care Physician

A primary care physician is a point of first contact. This group of specialties classically includes family medicine, internal medicine, and pediatrics. Primary care physicians treat patients with "undifferentiated" health concerns and must diagnose patients based on signs, symptoms, and clinical history.

The scope of primary care medicine is broad and involves any organ system or diagnosis as well as any other biological, psychological, or social issues.

According to the American Academy of Family Physicians (AAFP), here are some responsibilities of a primary care physicians:

  • Disease prevention
  • Health promotion
  • Counseling
  • Patient education
  • Health maintenance
  • Diagnosis and treatment of acute and chronic disease
  • Provision of health care in a variety of settings, such as outpatient (clinic, long-term care and so forth), and inpatient settings (including critical care)

Primary care physicians routinely engage in continuity of care and see patients during the course of a lifetime. Colloquially, when an adult man refers to his "doctor," he's probably referring to his internist or family medicine physician.

When needed, a primary care physician can refer a patient to a specialist and thus coordinate effective and comprehensive care.

General Internist

A general internist treats adult patients. General internists are primary care physicians who work both in inpatient (hospital) and outpatient settings. Some internists specialize in treating patients only in the hospital, and they're called hospitalists.

After medical school, general internists complete three years of residency or postgraduate training. After residency, these physicians can either practice as general internists or continue with specialty training.

General internists are experts at diagnosing and managing a variety of common conditions, including headache, gastroesophageal reflux disease (GERD), hypertension, and type 2 diabetes mellitus. Internists manage medication regimens, prescribe medications, counsel patients on medication use and adverse effects as well as check medications for potentially dangerous interactions.

Here are some specific subspecialties, or fellowships, that internists can pursue after completing residency. A typical internal medicine fellowship lasts three years but can continue even longer with even further subspecialization.

Internists who subspecialize in these fields receive further exposure to specific organ systems or groups of organ systems. Furthermore, internists who subspecialize are qualified to manage very complex medical presentations and perform complex procedures. In the list below, the names of these types of physicians are in parentheses.

  • Allergy and immunology (allergist and immunologist)
  • Endocrinology, diabetes and metabolism (endocrinologist)
  • Hematology or blood disorders (hematologist)
  • Gastroenterology (gastroenterologist)
  • Oncology or cancer medicine (oncologist)
  • Nephrology or kidney (nephrologist)
  • Pulmonary or lung disease (pulmonologist)
  • Rheumatology or joints (rheumatologist)
  • Cardiology or heart medicine (cardiologist)

Cardiology is a complex field and cardiologists can further specialize in interventional cardiology, clinical cardiac electrophysiology, and advanced heart failure and transplant cardiology.

The pulmonary disease fellowship training is ften combined with critical care and a person who practices in a critical care setting is called an intensivist.

Family Physician

A family physician or family medicine physician is a doctor who is qualified to treat all members of the family, including babies, children, adolescents, adults, and older adults. Family physicians not only treat general medical conditions but also are responsible for health maintenance and can direct their patients to appropriate consultants, health services, and community resources.

Furthermore, a family physician engages in preventive health care, which entails measures focused on the prevention of future illness. These measures could include diagnostic testing, such as cholesterol or blood sugar testing, or counseling on weight loss, smoking cessation, alcohol misuse, and so forth.

Family physicians treat a wide gamut of illnesses ranging from upper respiratory infections to skin infections to hypertension and diabetes. Furthermore, many family physicians perform small outpatient medical procedures such as lancing an abscess or suture removal.

Like internists, family physicians complete three years of residency or postgraduate training. Family medicine physicians can specialize in other areas, including sports medicine and geriatrics (elderly care). A physician who practices geriatrics is called a geriatrician. Finally, geriatrics is also a subspecialty of internal medicine.

Many family physicians take exception to the term "family practice physician." These specialists claim that they're not "practicing" anything and are specialists too.


Pediatricians care for the physical, mental, and social health concerns of children and treat patients through early adulthood. They also diagnose and treat acute and chronic diseases as well as engage in preventive health care (think the administration of vaccines and health counseling).

Similar to a general internist, a pediatrician can be a primary care pediatrician. Furthermore, there are pediatric medical subspecialists who specialize in diverse fields much like an internist can with the fundamental difference being that internists care for adults and pediatricians care for children.

Pediatricians complete three years of residency with further years of subspecialty training. Common conditions that a pediatrician treats include upper respiratory infections, ear infections, diarrhea, and so forth.


Obstetrician-gynecologists (OB-GYNs) care for the reproductive needs of women. They also care for women during pregnancy and delivery. The practice of obstetrics and gynecology is both medical and surgical with OB-GYNs performing a variety of surgical procedures like hysterectomy, or the removal of the uterus.

Obstetrics-gynecology is a four-year residency. Furthermore, OB-GYNs can further specialize in fields such as reproductive endocrinology, maternal fetal medicine, and reproductive endocrinology and fertility.

Writing OB-GYN as OB/GYN (with a solidus or slash) rather than OBGYN is discouraged by many medical editors, although the Associated Press style is OB-GYN. The slash has an imprecise function and can suggest an "either...or" construction, which is inaccurate because many OB-GYNs practice both obstetrics and gynecology.


General surgery is a five-year residency program that trains physicians to diagnose and treat a variety of diseases using surgery. After surgery residency, general surgeons (surgeons who practice straight away without further residency training) typically perform the following surgeries:

  • Colon cancer surgery (think bowel resection or removal)
  • Hemorrhoid surgery
  • Varicose veins
  • Cholecystectomy or removal of the gallbladder

Of note, general surgeons are trained to perform both laparotomies, or open incisions of the abdominal cavity, or laparoscopy, which entails use of a laparoscope, or a flexible tube with a light at the end of it. Laparoscopy is a minimally invasive procedure with the laparoscope and surgical instrumentation introduced to the body via a small incision and inflation of the abdominal cavity.

After completing residency, many surgeons go on to subspecialize. Here are some fellowships that surgeons can pursue:

  • Pediatric surgery
  • Cardiothoracic surgery (think heart surgery)
  • Vascular surgery (surgery on blood vessels, such as creation of arteriovenous fistulas for dialysis and so forth)
  • Solid organ transplantation
  • Bariatric surgery
  • Hand surgery

More generally, the practice of medicine can be broadly divided into two foci: medicine and surgery. Medicine refers to the internal medicine specialties which are nonsurgical. Please note that certain surgical residencies and fellowships are distinct from general surgery, such as neurosurgery and urology.


Psychiatry is a medical specialty that focuses on the diagnosis, treatment, and prevention of behavior disorders, mental disorders, and emotional disorders.

Please note that although there is an overlap between the two professions, psychiatrists and psychologists are fundamentally different health practitioners. Specifically, psychiatrists are physicians and have either an MD or DO degree.

Psychiatry residency lasts four years. Here are some psychiatric subspecialties:

  • Addiction psychiatry
  • Child and adolescent psychiatry
  • Geriatric psychiatry
  • Recovery-oriented care

Please note that a neurologist is a physician who specializes in the diagnosis and treatment of disorders of the nervous system. Although there's overlap between the two fields, a neurologist focuses on organic disease. For example, a neurologist can provide treatment for acute illness such as stroke or chronic illness such as multiple sclerosis or dementia.

Interestingly, the fields of neurology and psychiatry share a common past and diverged over time. Many neurological diseases present with psychiatric symptoms. Furthermore, psychiatric conditions can manifest as organic neurological illness.

The common origins of these fields is apparent in both types of residency training programs, with psychiatry residents receiving plenty of exposure to neurology, and neurologists receiving exposure to psychiatry, too. In fact, psychiatrists receive certification by taking the American Board of Psychiatry and Neurology.

A Word from Verywell

The information in this article expatiating various medical specialties is by no means comprehensive. Several specialties and subspecialties have not been reported here, including radiology, physical medicine and rehabilitation (PM&R), hematology, infectious disease, and so forth.

Moreover, the actual length of certain residency and fellowship programs can sometimes vary. Finally, there are certain permutations and combinations of post-graduate training. For instance, some physicians perform combined residencies in both internal medicine and pediatric (Med-Peds).

If you have any questions about the role of your physician, please search the relevant association websites and feel free to ask your physician during a visit. It's always great to be informed about all aspects of your care including what exactly your physician does and treats.

5 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. American Academy of Family Physicians. Primary care.

  2. Committee on Pediatric Workforce. Definition of pediatrician. Pediatrics. 2015;135(4):780-781. doi:10.1542/peds.2015-0056

  3. American Board of Obstetrics & Gynecology. Definition of an obstetrician and gynecologist.

  4. The American Board of Surgery. Specialty of general surgery defined.

  5. American Psychiatric Association. What is psychiatry?

By Naveed Saleh, MD, MS
Naveed Saleh, MD, MS, is a medical writer and editor covering new treatments and trending health news.