cramp cramp a cramp is a sudden, involuntary, painful skeletal muscle contraction or overshortening associated with electrical activity; while generally temporary and non-damaging, they can cause significant pain and a paralysis-like immobility of the affected muscle. a cramp usually goes away on its own over a period of several seconds, or minutes. cramps are common and tend to occur at rest, usually at night (nocturnal leg cramps). they are also often associated with pregnancy, physical exercise or overexertion, age (common in older adults), in such cases, cramps are called idiopathic, because there is no underlying pathology. in addition to those benign conditions cramps are also associated with many pathologic conditions. not to be confused with seizure or spasm. crampsymptomssudden muscle pain and a paralysis-like immobilitytreatmentquinine, stretching, massage, and drinking liquids cramp definition is narrower than the definition of muscle spasm: spasms include any involuntary abnormal muscle contractions, while cramps are sustained and painful. true cramps can be distinguished from other cramp-like conditions. cramps are different from muscle contracture, which is also painful and involuntary, but which is electrically silent. the main distinguishing features of cramps from dystonia are suddenness with acute onset of pain, involvement of only one muscle and spontaneous resolution of cramps or their resolution after stretching the affected muscle. restless leg syndrome is not considered the same as muscle cramps and should not be confused with rest cramps. skeletal muscle, with myofibrils labeled at upper right and sarcoplasmic reticulum at bottom causes 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 hypomagnesemia). some skeletal muscle cramps do not have a known cause. motor neuron disorders (e.g., amyotrophic lateral sclerosis), metabolic disorders (e.g., liver failure), some medications (e.g., diuretics and inhaled beta‐agonists), and haemodialysis may also cause muscle cramps. causes of cramping include hyperflexion, hypoxia, exposure to large changes in temperature, dehydration, or low blood salt. muscle cramps can also be a symptom or complication of pregnancy; kidney disease; thyroid disease; hypokalemia, hypomagnesemia, or hypocalcaemia (as conditions); restless legs syndrome; varicose veins; and multiple sclerosis. as early as 1965, researchers observed that leg cramps and restless legs syndrome can result from excess insulin, sometimes called hyperinsulinemia. skeletal muscle cramps