The pain at the back of the thigh can be caused by the following reasons: first, pain caused by fasciitis at the back of the thigh due to cold and strain, which can have pain at the back of the thigh at the fascia, which should be diagnosed by early examination and examination to exclude other diseases. Second, the pear-shaped muscle syndrome, pear-shaped muscle syndrome patients can have pain in the hip pear-shaped muscle walk, can be accompanied by nerve compression and lead to neuropathic pain in the posterior thigh, this time to early physical examination, check the lower limb nerve electromyography to early diagnosis and treatment. Third, lumbar spine diseases, when lumbar disc herniation, lumbar spinal stenosis, or lumbar spine tuberculosis, tumor and lumbar spine serious slippage compression of nerve roots, there can be lower limb neuropathic pain, can be radiated from the thigh to the calf and foot pain, then to check the lumbar spine MRI, CT, X-ray to early diagnosis and treatment.