Good health is a presumption upon which everything else is planned. Until antibiotics were developed in the 1940’s, health was mainly dependent upon body resistance, minimal exposure to sick people, and control of other disease vectors. Doctors were unable to cure most diseases, and their services were needed mainly for accidents. Home medicines were used for all but life-threatening illnesses. Today, excellent medical services are available in large cities, but intelligent self-diagnosis is important in small towns and isolated rural areas. People should learn as much as possible about their chronic diseases and conditions.