Delirium tremens, often called the DT's, is a nervous and mental disturbance that results from acute alcoholism. Many people become markedly disturbed and develop delirium tremens after unusually prolonged or heavy drinking of alcoholic beverages. They develop insomnia and a dislike for food, and become irritable and restless. They may then have visual illusions and hallucinations that are brief but terrifying. The condition itself may last from 3 to 10 days. Death sometimes results, often because pneumonia or heart failure develops. Doctors usually treat delirium tremens by taking alcohol away from patients and giving them sedative and tranquillizing drugs.