There are many common causes of calf hamstring pain and excruciating walking pain. Deep vein thrombosis, primary lower extremity venous valve insufficiency, especially in the presence of thrombophlebitis, the pain is more pronounced. Sacroiliac joint lesions, occlusive atherosclerosis, pheochromocytoma, lumbar spinal stenosis, peroneal nerve entrapment syndrome, rheumatoid arthritis, tenosynovitis, tenosynovial cysts, malignant tumors of the lower leg, peripheral neuropathy caused by diabetes mellitus, and strained injuries of the lower leg muscles can cause pain in the leg. In addition, it is necessary to take the appropriate treatment according to the cause of severe pain in the leg in order to achieve good results. For the following situations, you should go to the hospital for timely consultation, such as painful unilateral leg, can not keep walking comfortably, the injury caused by the deformity of the calf, the pain still exists when resting or sleeping, and the pain persists for many days with swelling, redness and fever of the calf or ankle joint.