Children sleeping at night called leg pain, consider is due to localized cold, growing pains, excessive exercise, calcium deficiency and other factors. 1. localized cold: small children sleeping at night leg pain, may be due to the legs due to cold, such as when sleeping, do not pay attention to the legs of the warmth, by the external temperature, thus producing leg cold and pain symptoms. 2. Growing pains: usually refers to children around the knee joint or the anterior side of the calf pain, this kind of children do not have obvious history of trauma, and the activities are normal, but in the night time when you sleep, there may be pain in the leg phenomenon, consider and production of pain related. 3. Excessive exercise: children sleeping at night with leg pain, can not be ruled out due to excessive activity during the day, resulting in lactic acid in the legs to gather, and then produce symptoms of pain. 4. Calcium deficiency: small children in the body of calcium and vitamin D deficiency, may also cause the child to appear leg pain and leg cramps and other symptoms. Children sleeping at night called leg pain, there may also be other reasons, it is recommended to go to the hospital in time, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.