Explanation:

A cramp is a sudden, involuntary muscle contraction or overshortening; while generally temporary and non-damaging, they can cause significant pain and a paralysis-like immobility of the affected muscle. Onset is usually sudden and it resolves on its own over a period of several seconds, minutes, or hours. Cramps may occur in a skeletal muscle or smooth muscle. Skeletal muscle cramps may be caused by muscle fatigue or a lack of electrolytes such as sodium (a condition called hyponatremia), potassium (called hypokalemia), or magnesium (called magnesium deficiency). Cramps of smooth muscle may be due to menstruation or gastroenteritis.A lactic acid buildup around muscles can trigger cramps; however, they happen during anaerobic respiration when a person is exercising or engaging in an activity where the heartbeat rises.