Acute illness or injury is a sudden onset with regard to illness or injury.

Acute illness means abnormal body condition with sudden, rapid onset. It usually remains for a short period of time. Acute illness can be cured on its own or may need some medications.

Acute injury is sudden and spontaneous. Acute injuries are usually the result of one traumatic event.

Acute diseases can become chronic if not treated properly and persist for a long period of time.