15-year-old boy leg cramps, the following reasons are common: First, calcium deficiency: 15-year-old boy is in the adolescent growth stage, the demand for calcium is greater, if the diet is not balanced, easy to lead to the phenomenon of calcium deficiency, the patient will be manifested as leg cramps symptoms, accompanied by leg pain, serum calcium ion will be found in the serum calcium concentration decreased significantly, timely supplementation of calcium can alleviate the clinical symptoms, the patient should usually have a balanced diet, avoiding partiality. Avoid partiality. Second, overwork: 15-year-old boy if the exercise is excessive, may produce leg muscle overwork, can also cause leg muscle cramps clinical symptoms, accompanied by leg muscle pain, muscle weakness, after timely rest, hot compresses, massage therapy, can make the clinical symptoms be relieved. It is best for patients to warm up before exercise and stretch the leg muscles after exercise to prevent the symptoms of leg cramps.