chronic

Chronic is an adjective used to describe conditions or phenomena that are long-lasting or recurring. In medical contexts, chronic conditions persist for extended periods, typically months or years, and may progress slowly over time. This is in contrast to acute conditions, which have a rapid onset and a relatively short duration. The term derives from the Greek chronos, meaning time.

In medicine, chronic diseases often require ongoing management rather than a one-time treatment. Examples include cardiovascular disease, diabetes, chronic respiratory diseases, and many autoimmune disorders. Definitions of what counts as chronic can vary, but many fields use a threshold such as three months or longer to distinguish chronic from acute. Treatment emphasizes long-term monitoring, prevention of complications, lifestyle modification, and sustained pharmacological or rehabilitative therapies. The prognosis varies widely by condition and may range from well-controlled disease to progressive decline.

In everyday language, chronic describes problems that are persistent or repeatedly occur, such as chronic pain or chronic stress. The term can be used in nonmedical contexts, but it may also be applied imprecisely, so specificity about duration, frequency, and etiology is important in professional settings. See also chronic disease, chronic pain, epidemiology, and prognosis for related topics.