Physician character jug wearing a tan hat and produced by Jane Holland of South Gate, California, circa 1945. A physician, medical practitioner, medical doctor, or simply doctor, is a health professional who practices medicine, which is concerned with promoting, maintaining or restoring health through the study, diagnosis, prognosis and treatment of disease, injury, and other physical and mental impairments. Physicians may focus their practice on certain disease categories, types of patients, and methods of treatment, known as specialties, or they may assume responsibility for the provision of continuing and comprehensive medical care to individuals, families, and communities, known as general practice. Both the role of the physician and the meaning of the word itself vary around the world. Degrees and other qualifications vary widely, but there are some common elements, such as medical ethics requiring that physicians show consideration, compassion, and benevolence for their patients.