The following causes are generally considered for calf cramps in the middle of the night: 1. Cold stimulation, local cold in the calf during sleep at night, can lead to calf muscle spasms and symptoms of calf cramps. In this case, attention should be paid to keep warm during sleep to prevent local cold. 2, low serum calcium, when the human serum calcium is low will cause calf muscle cramps, this situation is mostly seen in the middle-aged and elderly, especially in middle-aged and elderly women, such patients are mostly accompanied by osteoporosis, such patients can usually appropriate calcium supplements to help alleviate the symptoms of cramps. 3, fatigue, too much exercise during the day, sleep at night muscle The tension is not improved, it will cause calf cramps. If you have too much exercise during the day, you can massage your calves before bed and soak your feet in hot water to help relieve muscle tension. 4, lower limb vascular disease, patients suffering from lower limb arterial occlusive disease, due to nerve ischemia will appear at night calf muscle cramps, such patients need to go to the hospital for lower limb vascular ultrasound examination, and give symptomatic treatment to improve blood circulation and relieve symptoms.