Cramps in the legs that occur at night while sleeping are not only found in the elderly, but can occur in young people, men and women. The reason is that a long-term posture, the muscles are in a state of long-term tension, there will be spasm contraction caused by cramps. There is also a long-term fixed position, the circulation of the leg muscles is affected, such as compression, localized metabolite accumulation, will stimulate muscle contraction. There is also the local muscle stimulation by the cool, such as the legs are not covered, the muscle spasm, is also the cause of sleep cramps at night. Some people have localized blood flow disorders, such as diabetic peripheral vasculopathy and neuropathy, which can also cause sleep cramps in the legs. In other cases, due to a decrease in the level of calcium in the blood, not only leg cramps, but also twitching of the hands and feet may occur.