Inexplicable pain in the calf, commonly found in lower extremity arteriosclerosis, lumbar disc herniation, etc., as follows: first, elderly patients with lower extremity arteriosclerosis, patients will show lower extremity pain, especially calf pain, and cold, numbness, walking for a period of time, claudication, color ultrasound can be diagnosed with vascular blockage. Second, lumbar disc herniation, if for acute attack, the patient can directly have calf pain symptoms, and lumbar symptoms on the contrary is not obvious, and lumbar spine activities will not be restricted. In addition to calf pain, the patient will also have symptoms of calf numbness and even calf weakness, which can be diagnosed by MRI and CT scan. Thirdly, we should pay attention to the possibility of leg swelling, for example, primary bone tumor usually occurs in children’s lower limb bones, metastatic bone tumor usually occurs in the elderly, if there is progressive aggravation of calf pain, should be MRI, CT scanning and other tests to exclude. These are the common causes of inexplicable pain in the calf, after timely diagnosis, timely treatment, can make the clinical symptoms have been significantly relieved, ordinary life should pay attention to protect the lower limb blood vessels and lumbar intervertebral discs, to avoid the symptoms.