Chronic illness is a protracted painful process. It differs from an acute illness in that it occurs suddenly and either heals or becomes chronic. Well, or a person dies.
Chronic is, for example, tonsillitis (runny nose) or bronchitis. They heal quite successfully.
Some diseases become chronic simply because a person continues to abuse alcohol, tobacco and overeating. Half of all chronic ailments. Many problems are treated simply by dieting and an active lifestyle without medication.