Internal medicine is a specialized branch of medicine that focuses on the prevention, diagnosis, and non-surgical treatment of diseases affecting adults. Physicians specializing in internal medicine, often called “internists” or “doctors of internal medicine,” are trained to handle a wide range of complex medical conditions. Their expertise encompasses illnesses affecting the body’s internal organs and systems, such as the heart, lungs, liver, kidneys, gastrointestinal tract, and endocrine system. They are particularly skilled in managing chronic illnesses, diagnosing puzzling symptoms, and caring for patients with multiple co-existing conditions.