A certification by the Board of Internal Medicine. Practitioners provide long-term, comprehensive care in the office and the hospital, managing both common illnesses and complex problems for adolescents, adults, and the elderly. General internists are trained in primary care internal medicine, which incorporates an understanding of disease prevention, wellness, substance abuse, mental health, and treatment of problems of the eyes, ears, skin, nervous system and reproductive organs. All internists are trained in the subspecialty areas of internal medicine including emergency internal medicine and critical care. Internists consult with surgeons when surgical management is indicated, and often act as consultants to other specialists.