The clinical manifestations of cramps are transient muscle spasms in the muscle groups, mainly in the limbs, which form hard nodules and lead to muscle pain and restriction of muscle activity, unable to fulfill normal diastolic function. Physical examination can feel the muscle stiffness, muscle hard nodules and nodules at the pressure pain is very obvious, the neighboring joints show passive activity phenomenon, the patient is more painful, need to be assisted by others as soon as possible to relieve the pain symptoms, the specific approach can be reversed with muscle spasm and muscle tension, so that the muscles gradually relax, you can quickly relieve the pain of the cramp, the local hot compresses can also alleviate the pain. The cause of cramps is usually overwork or excessive exercise caused by the accumulation of internal muscle damage caused by subtle, muscle cold can be induced by the occurrence of cramps.