In the middle of the night there is a sharp pain in the calf is seen in the following cases: first, occur in the arterial system of disease. Especially in the middle-aged and elderly male patients appear more, there is a history of smoking, hypertension, diabetes, in addition to coronary artery disease, atrial fibrillation, etc. will appear thromboembolism, and even acute embolism of the arteries of the lower limbs. Therefore, the patient will show obvious pain, also accompanied by fever, nausea and vomiting, and the examination will find that the distal limb is obviously pale and cold, or even abnormal sensation, and the dorsal artery of the foot can not be touched. In the acute stage, emergency surgery should be performed to remove the thrombus embolus, and postoperative symptomatic treatments such as preventing infection and improving microcirculation should be performed. Second, occur in the venous system of disease, that is, deep vein thrombosis of the lower extremities, urge the patient to dorsiflexion of the foot will be manifested as obvious symptoms of gastrocnemius muscle pain.