Internal Medicine or General Medicine is the medical specialty dealing with the prevention, diagnosis, and treatment of adult diseases. Physicians specializing in general medicine are called internists or physicians (without a modifier). Physicians are skilled in the management of patients who have undifferentiated or multi-system disease processes. Physicians care for hospitalized and ambulatory patients and may play a major role in teaching and research. Because internal medicine patients are often seriously ill or require complex investigations, physicians do much of their work in hospitals. Physicians often have subspecialty interests in diseases affecting particular organs or organ systems. General medicine is also a specialty within clinical pharmacy and veterinary medicine.