The leg has been cramping clinically known as leg muscle spasm, leg muscle spasm may be the lower extremity vascular disease, peripheral nerve compression and so on. 1. Lower extremity vascular disease: normal muscle tissue is rich in oxygen, ischemia, hypoxia environment is more sensitive. When the lower extremity vascular disease, will lead to muscle tissue gas exchange, material circulation obstacles, muscle anaerobic metabolism increases, resulting in lactic acid and other metabolic products accumulation, muscle spasm, common diseases such as varicose veins of the lower extremities, arterial occlusive vasculitis. 2. Peripheral nerve compression: the nerves that innervate the muscles of the lower limbs are mainly the sciatic nerve, when the sciatic nerve is compressed due to various reasons, it will lead to abnormal electrophysiological signals that innervate the muscles of the legs, and it may also be manifested as muscle spasms of the legs, with common diseases such as pectus carinatum, lumbar intervertebral disc protrusion, lumbar vertebral spondylolisthesis, and so on. There may also be other reasons for leg cramps, 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.