Leg cramps in medicine, also known as muscle spasms, is a spontaneous tonic contraction of the muscles, often occurring in the calf and toe muscles, in the leg cramp attack is often painful, many patients in the middle of the night twitching will be woken up by the pain affecting the sleep, the common causes of leg cramps are the following reasons: a cold, in the outside world of the cold stimulus, the muscles will be spontaneous spasms, which will appear leg cramps, especially in the In the middle of the night when the cramps are more significant. Second, excessive exertion or excessive exercise, fatigue, poor rest will also appear muscle spasms, due to the accumulation of local muscle acidic metabolites and lead to muscle spasms. Third, the decline of estrogen, osteoporosis can also lead to muscle contraction and spasm, due to osteoporosis when the blood calcium level is reduced, muscle spasm.