A disease that persists for a long time. A chronic disease is one lasting 3 months or more, by the definition of the U.S. National Center for Health Statistics. Chronic diseases generally cannot be prevented by vaccines or cured by medication, nor do they just disappear. Eighty-eight percent of Americans over 65 years of age have at least one chronic health condition (as of 1998). Health damaging behaviors - particularly tobacco use, lack of physical activity, and poor eating habits - are major contributors to the leading chronic diseases. See the entire definition of Chronic disease
A disease which has one or more of the following characteristics: (1) is permanent, leaves residual disability; (2) is caused by nonreversible pathological alternation; (3) requires special training of the patient for rehabilitation, or may be expected to require a long period of supervision, observation, or care.