Doctors of internal medicine focus on adult medicine and have had special study and training focusing on the prevention and treatment of adult diseases. Internists are trained in the diagnosis and treatment of infections, and diseases affecting the heart, blood, kidneys, and digestive, respiratory, and vascular systems.
They are also trained in the essentials of primary care internal medicine which incorporates an understanding of disease prevention, wellness, substance abuse, mental health, and effective treatment of common problems of the eyes, ears, skin, nervous system, and reproductive organs.