Muscle cramps are involuntary muscle contractions that may last anywhere from a few seconds to a few minutes. They usually happen suddenly and can be very painful. The cramp can often be seen, and the affected muscle may be hard to the touch. While muscle cramps can be associated with certain serious conditions, this is rare.[1]
There are several types of muscle cramps. In active individuals, cramps are termed exercise associated muscle cramps (EAMC). Muscle cramps in the legs or feet in bed are often termed rest cramps, or nocturnal leg cramps.[1]