The causes of pain in the calf muscle include physiological and pathological causes. 1. Physiological causes: mainly due to muscle fatigue injury, cold and other reasons. Physiological causes will appear muscle anaerobic metabolism, resulting in the accumulation of lactic acid, oxygen free radicals and other metabolites, stimulation of the nerve root induced pain. Most of the physiological causes are self-healing, and the symptoms can be relieved after braking and resting. 2. Pathological causes: Pathological causes are mainly due to lesions of nerves, muscles and blood vessels. The common ones include lumbar disc herniation, spinal stenosis, lower extremity venous thrombosis, gastrocnemius muscle tear, etc. Pathological causes are often combined with concomitant symptoms such as lumbar pain, lower extremity edema, and functional limitation. After external stimulation, there is often a manifestation of aggravation of symptoms. Based on the symptoms of calf muscle pain when pinched inside can not accurately determine the cause, but also need to be combined with the characteristics of the medical history, other test results to make an accurate judgment, it is recommended that the cause of the disease under the guidance of a doctor.