Internal medicine is the medical specialty dealing with the prevention, diagnosis, and treatment of adult diseases. Doctors of Internal Medicine, also known as internists, are sometimes referred to as the "doctor's doctor," because they are often called upon to act as consultants to other physicians to help solve puzzling diagnostic problems. They are especially skilled in the management of patients who have undifferentiated or multi-system disease processes. An internist cares for hospitalized and ambulatory patients and may play a major role in teaching or research. Internal medicine is also a type of veterinary specialty.
The term internal medicine comes from the German term innere Medizin, popularized in Germany in the late 1800s to describe physicians who combined the science of the laboratory with the care of patients. Many early-20th-century American doctors studied medicine in Germany and brought this medical field to the United States. Thus, the name "internal medicine" was adopted. Specialists in internal medicine are commonly called internists. Elsewhere, especially in Commonwealth nations, such specialists are often called physicians. Because their patients are often seriously ill or require complex investigations, internists do much of their work in hospitals. Formerly, many internists were not subspecialized and would see any complex nonsurgical problem; this style of practice has become much less common.
In modern practice, most internists are subspecialists; that is, in general, they limit their medical practice to problems of one organ system or to one particular area of medical knowledge. For example, gastroenterologists and nephrologists specialize in diseases of the gut and the kidneys, respectively.
Internists have a lengthy clinical and scientific training in their areas of medical interest and have special expertise in the use of prescription drugs or other medical therapies (as opposed to surgery).
 Definition of an internist
Internists are Doctors of Internal Medicine and are referred to by several terms, including "general internists" and "doctors of internal medicine." The term may be confused with "interns," who are doctors in their first year of residency training. Although internists may act as primary-care physicians, they are not "family physicians," "family practitioners," or "general practitioners," whose training is not solely concentrated on adults and may include surgery, obstetrics, and pediatrics.
 Education and training of internists
The training and career pathways for internists vary considerably across the world.
First, they must receive the "entry-level" education required of any medical practitioner in the relevant jurisdiction. The entry-level for medical education programs are tertiary-level courses, undertaken at a medical school attached to a university.
Programs that require previous undergraduate education are usually four or five years in length. Hence, gaining a basic medical education may typically take eight years, depending on jurisdiction and university. Following completion of entry-level training, newly graduated medical practitioners are often required to undertake a period of supervised practice before the licensure, or registration, is granted, typically one or two years. This period may be referred to as, "internship" or "conditional registration." Then, internists require specialist training in internal medicine or one of its subspecialties. In North America, this postgraduate training is often referred to as residency training; in Commonwealth countries, such trainees are often called registrars.
Training in medical specialties typically takes from three to 10 years, and sometimes more, depending on specialty and jurisdiction. A medical practitioner having completed specialist training in internal medicine (or in one of its subspecialties) is an internist, or a medical specialist in the older, narrower sense. In some jurisdictions, training in internal medicine is begun immediately following completion of entry-level training, or even before. In other jurisdictions, a medical specialist must undertake generalist (un-streamed) training for one or more years before commencing specialization. Hence, depending on jurisdiction, an internist typically takes 12 or more years after commencing basic medical training â€” five to eight years at university to obtain a basic medical qualification and up to another six years to become a medical specialist. Internal Medicine subspecialists may also practice general internal medicine, but a particular subspecialty; for example, cardiology or pulmonology licensure is granted after completing a fellowship (Additional training of 2â€“3 years).
 Subspecialties of internal medicine
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.
 American 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 chemotherapeutic (chemical) 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.
- Adolescent medicine
- Clinical cardiac electrophysiology
- Critical care medicine
- Geriatric medicine
- Interventional cardiology
- Hospital medicine
- Sleep medicine
- Sports medicine
- Transplant hepatology
Internists may also specialize in "allergy" and "immunology." The American Board of Allergy, Asthma, and Immunology is a conjoint board between internal medicine and pediatrics.
 American College of Osteopathic Internists
The American College of Osteopathic Internists recognizes the following subspecialties.
 Medical diagnosis and treatment
Medicine is mainly focused on the art of diagnosis and treatment with medication, but many subspecialties administer surgical treatment:
 See also
 External links