In medicine, a chronic disease is a disease that is long-lasting or recurrent. The term chronic describes the course of the disease, or its rate of onset and development. A chronic course is distinguished from a recurrent course; recurrent diseases relapse repeatedly, with periods of remission in between. As an adjective, chronic can refer to a persistent and lasting medical condition. Chronicity is usually applied to a condition that lasts more than three months.
The definition of a disease or causative conditon may depend on the disease being chronic, and the term will often appear in the description:
- Chronic obstructive pulmonary disease
- Chronic fatigue syndrome
- Chronic hepatitis
- Chronic leukemia
- Chronic arthritis