What is a disease?
A disease is a term for a problem with health. This may involve a physical or psychological condition. An illness is an impediment to normal functioning and is accompanied by symptoms that give an indication that an illness is present.
Known diseases
The most well-known and common diseases are influenza, respiratory infections and depression (psychological). The most well-known and common deadly diseases are cardiovascular disease and cancer. Fortunately, diseases can also be cured, with or without treatment. Prevention of disease is possible through several factors such as adequate exercise, healthy and varied diet, adequate sleep, no to minimal stress exposure. Sometimes disease is hereditary.