Leg cramps at night are a spontaneous and obligatory contraction of the muscles, which can be very painful, especially if it wakes you up, and it is difficult to stop the pain for a long period of time, which can affect your sleep. Cramps at night can be caused by calcium deficiency. In this case, it is caused by growth and development, which is also a manifestation of growth, but the cramps are not necessarily caused by a lack of calcium alone, but also caused by many other situations. Cold stimulation, such as sleeping at night without a good blanket, calves by the cold stimulation, will spasm caused by cramps. Muscle continuous contraction too fast, excessive sweating, excessive fatigue, bad sleep posture, etc., especially sleep posture, such as a long time lying on the back so that the quilt presses the foot, or a long time lying on the stomach so that the foot against the bed, so that some muscles of the calf for a long time in an absolute state of relaxation, caused by passive contracture of the muscle. In addition, there may also be related to vascular lesions, therefore, for patients with night cramps, first of all, should be related to the examination, to further clarify the specific causes of the disease, in order to give the appropriate treatment.