Subspecialties of internal medicine

Internists can choose to focus their practice on general internal medicine, or may take additional training to "subspecialize" in one of 13 areas of internal medicine, generally organized by organ system. Cardiologists, for example, are doctors of internal medicine who subspecialize in diseases of the heart. The training an internist receives to subspecialize in a particular medical area is both broad and deep. Subspecialty training (often called a "fellowship") usually requires an additional one to three years beyond the standard three year general internal medicine residency. (Residencies come after a student has graduated from medical school.)

In the United States, there are two organizations responsible for certification of subspecialists within the field, the American Board of Internal Medicine, and the American Osteopathic Board of Internal Medicine.

The following are the subspecialties recognized by the American Board of Internal Medicine.

* Cardiology, dealing with disorders of the heart and blood vessels
* Endocrinology, dealing with disorders of the endocrine system and its specific secretions called hormones
* Gastroenterology, concerned with the field of digestive diseases
* Hematology, concerned with blood, the blood-forming organs and its disorders
* Infectious disease, concerned with disease caused by a biological agent such as by a virus, bacterium or parasite
* Medical oncology, dealing with the study and treatment of cancer
* Nephrology, dealing with the study of the function and diseases of the kidney
* Pulmonology, dealing with diseases of the lungs and the respiratory tract
* Rheumatology, devoted to the diagnosis and therapy of rheumatic diseases.

Definition of an Internist

Internists hold a medical degree. They are not to be confused with "Medical Interns," who are either physicians in their first year of residency training (in countries like the USA), or last-year medical students (in countries like Colombia). Although Internists may act as primary care physicians, they are not "family physicians," "family practitioners," or "general practitioners" (whose training in certain countries includes the medical care of children, and may include surgery, obstetrics and pediatrics). General Internists practice medicine from a primary care perspective but they can treat and manage many ailments and are usually the most adept at treating a broad range of diseases affecting adults.

Internal Medicine sub-specialists may also practice general internal medicine, but can focus their practice on their particular subspecialty like cardiology or pulmonology after completing a fellowship. (Additional training of 2-3 years)

In the USA, adult primary care is usually provided by either family practice or general internal medicine physicians. The primary care of adolescents is provided by family practice, internists and pediatricians. The primary care of children and infants is provided by Family Practice or Pediatricians, thus, there is overlap. These physicians can have either an MD, MDCM, MBBS, MBChB, BMBS, BMed, MBBChir, or DO degree.

Caring for the whole patient:

Internists are trained to solve puzzling diagnostic problems and handle severe chronic illnesses and situations where several different illnesses may strike at the same time. They also bring to patients an understanding of preventive medicine, men's and women's health, substance abuse, mental health, as well as effective treatment of common problems of the eyes, ears, skin, nervous system and reproductive organs. Most older adults in the United States see an internist as their primary physician.