Cramps are unpleasant, often painful sensations caused by muscle contraction or overshortening. The common causes of skeletal muscle cramps are muscle fatigue and a sodium imbalance.
Causes of cramping include hyperflexion, hypoxia, exposure to large changes in temperature, dehydration, or low blood salt. Muscle cramps may also be a symptom or complication of pregnancy, kidney disease, thyroid disease, hypokalemia, or hypocalcemia (as conditions), restless-leg syndrome, varicose veins, and multiple sclerosis. Nocturnal leg cramps are involuntary muscle contractions that occur in the calves, soles of the feet, or other muscles in the body during the night or (less commonly) while resting. Only a few fibers of a muscle may be activated. The duration of nocturnal leg cramps is variable with cramps lasting anywhere from a few seconds to several minutes. Muscle soreness may remain endure after the cramp ends. These cramps are erroneously believed to be more common in older people. They happen quite frequently in teenagers and in some people while exercising at night. Usually, putting some pressure on the affected leg by walking some distance will end the cramp.
The precise cause of these cramps is unclear. Potential contributing factors include dehydration, low levels of certain minerals (magnesium, potassium, calcium, and sodium), and reduced blood flow through muscles attendant in prolonged sitting or lying down. Less common causes include more serious conditions or drug use.
Nocturnal leg cramps may sometimes be relieved by stretching the affected leg and pointing the toes upward. Quickly standing up and walking a few steps may also shorten the duration of a cramp.
Nocturnal leg cramps (almost exclusively calf cramps) are considered to be â€˜normalâ€™ during the late stages of pregnancy. They can, however, vary in intensity from mild to incredibly painful.