Cramps in the calves while sleeping may be related to cold stimulation, excessive fatigue, calcium and potassium deficiency. 1. Cold stimulation: such as low indoor temperature when sleeping at night, or long-term exposure of the legs, resulting in wind-cold stimulation and muscle cramps. 2. Excessive fatigue: due to some high-intensity exercise in daily life, resulting in excessive fatigue of the lower limbs, the accumulation of metabolic lactic acid can not be discharged, leading to muscle spasm in the legs. 3. Calcium and potassium deficiency: due to the lack of calcium or potassium in the body, the electrolyte imbalance in the body, resulting in abnormal excitation of the calf muscles, muscle stress increases, resulting in leg cramps. Calf cramps while sleeping, it is recommended to consult a doctor in a timely manner, follow the doctor’s instructions for further examination, with the help of the doctor to clarify the cause, and targeted treatment or therapy.