A branch of medicine that specializes in treating all non-surgical dimensions of disease. Internal medicine is the medical specialty that deals with the prevention, diagnosis, and treatment of adult diseases. Doctors who specialize in internal medicine are called internal medicine specialists. They are especially adept at dealing with patients who have multiple undifferentiated or systemic diseases.
Internists care for patients in hospitals and outpatient clinics and can play a major role in teaching and research. Internal medicine doctors rely on diagnosis and the use of laboratory and diagnostic methods. The term was important at the beginning of the development of medicine and the separation of medical specialties to distinguish medical work from surgical work, which was called hand work, which was not recognized in medicine and considered less than medicine. Internal doctors study all diseases of the body, and therefore they are the most familiar with the interrelationship of diseases and medical conditions between the various organs, and therefore they are called to solve the problems of coordination between doctors and the link between symptoms and complaints.
The internist is prepared to deal with any problem faced by the patient, no matter how common, rare, simple or complex. He is specially trained to solve baffling diagnostic problems and can deal with chronic diseases and conditions that confront different diseases at the same time. He also prepares the patient to understand wellness, disease prevention, health promotion, women's health, substance abuse, and mental health, as well as the effective treatment of common problems of the eyes, ears, skin, nervous system and reproductive system.
In today's complex medical environment, internists take great pride in caring for their patients throughout their lives in the office or clinic, in hospital or intensive care, and in nursing homes, when they partner with other medical specialties, such as surgeons or obstetricians, to coordinate their patients' care and solve difficult medical problems associated with those care. But the development of medicine in all fields has increased medical specializations and internal medicine has branched out into different specializations:

• esoteric departments
• General internal medicine and digestive system
• heart disease
• breast diseases
• Kidney and urinary tract diseases
• Endocrinology and diabetes
• Rheumatology and rheumatism
• Blood diseases
• Tumors
• Communicable and infectious diseases
• Geriatrics
• Sports medicine
• Allergy and Immunology