Midnight leg and stomach cramps may be caused by overwork, cold and calcium deficiency. 1. Overwork: If the patient is overworked during the day, the calf muscles are fatigued, resulting in a large accumulation of lactic acid and other acidic substances in the calf muscles, it is easy to appear in the middle of the night leg and stomach cramps. 2. Cold: in the middle of the night, the calf is exposed, by the external cold stimulation, resulting in cold calves, calf skeletal muscle contraction and poor local blood circulation, easily lead to calf muscle spasm, that is, cramps. 3. Calcium deficiency: Calcium is an important ion to realize the function of muscle signaling, nerve transmission, muscle contraction, etc. If the body is deficient in calcium, it will lead to muscle conduction dysfunction, and the symptoms of cramps in the middle of the night leg and stomach. When the symptoms of leg and stomach cramps in the middle of the night, it is recommended that patients seek medical attention in a timely manner to confirm the cause of the disease and carry out targeted treatment.