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Understanding Internal Medicine

Internal medicine is the medical specialty that focuses on the care of adult patients, and internal medicine physicians are specialists who apply scientific knowledge and clinical expertise to the diagnosis, treatment, and compassionate care of adults across the spectrum from health to complex illness.

Although this definition seems fairly straightforward, it does not fully capture the breadth and richness of internal medicine as a medical discipline or the degree of its importance in our health care system.

Internal medicine is the world’s largest medical specialty, with nearly 200,000 internists practicing in the United States. Clinically, internal medicine physicians practice in an extremely wide range of roles and settings:

  • Internal medicine physicians are trained in the comprehensive care of patients and may function as generalist physicians practicing primary care, hospital medicine, or both.
  • Internal medicine physicians may also undergo additional training to focus their practice in one of the recognized subspecialty areas within internal medicine.
  • Internal medicine also carries a strong emphasis on research. Internal medicine physicians may be involved in basic science discovery, but also are prominent in translating basic science knowledge to clinical practice. As a specialty, up to two-thirds of all clinical research funding through the National Institutes of Health (NIH) is awarded to internal medicine physicians, and Departments of Medicine occupy a key role in research at our nation’s academic medical centers.
  • Medical education is also an important activity undertaken by internists as the nature of internal medicine and its wide-ranging clinical and research activities equip internal medicine physicians to teach medical students, residents and fellows.

Despite these widely varied activities and roles, the specialty is unified by a shared set of basic principles exemplified by the discipline's founder, Sir William Osler, that form the foundation of internal medicine practice:

  • Internal medicine emphasizes a thorough understanding of the science underlying the practice of medicine and the need to develop a comprehensive fund of knowledge of disease gained through study, observation, and experience in the care of patients, leading to a mastery of the complex inter-relationships of science and disease.
  • Internal medicine physicians believe that treatment of disease should be based upon scientific principles and our best understanding of what works and what does not.
  • Internal medicine physicians value the ongoing development and refinement of their own skills in understanding illnesses and their treatment, and as much as possible, contributing new information to our overall knowledge of health and disease.
  • Internal medicine physicians appreciate that physicians occupy a unique role in the lives of our patients and in society, and are obligated to bring our personal best to providing scientifically-based, compassionate, and high value care to our patients by balancing the understanding of the scientific aspects of medicine with the human and societal impact of disease.

Thus, internal medicine is perhaps best defined by its unique approach to medicine and its "scientific attitude" rather than by a specific group of patients being cared for, the practice setting, or research activity being pursued.