Leg cramps are medically known as “muscle spasms”. Common causes of muscle spasms include calcium deficiency, exertion or cold, excessive sweating, and poor sleeping posture. 1. Calcium deficiency: When there is a lack of calcium in the body, muscle excitability increases and muscle spasms are likely to occur. 2. Exhaustion or exposure to cold: If you suddenly engage in strenuous sports or a lot of physical labor, you may suffer from leg muscle spasms due to exertion, resulting in leg cramps. Usually after rest can be relieved. In addition, when sleeping at night, the calf stomach is cold, pressure, can also cause cramps. 3. Excessive sweating: If you sweat a lot during strenuous exercise, it can lead to electrolyte deficiency and cause leg cramps. 4. Bad sleeping position: If you lie on your back for a long time with the top of your feet pressed against the quilt, or lie prone for a long time with the top of your feet against the bed, it will make the muscles of the calf in a relaxed state for a long time, which will easily cause muscle spasms. Leg cramps may also be caused by other reasons, frequent leg cramps may be related to vascular disease, should go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, give targeted treatment or treatment.