Soreness at the back of the thighs may be caused by muscle strain, trauma, lumbar disc herniation and other factors, which can be dealt with through general treatment, medication and surgery. 1. Muscle strain: The back of the thigh is sore due to muscle strain caused by not stretching after strenuous exercise, which increases the secretion of creatine kinase. Appropriate rest can relieve the soreness to a certain extent. 2. Trauma: Due to strong impact or fall, the muscles in the thigh area will be damaged, resulting in poor local blood circulation and soreness. Non-steroidal anti-inflammatory drugs such as ibuprofen and celecoxib can be used for treatment as prescribed by the doctor. 3. Lumbar disc herniation: the herniated part may compress the nerve root, leading to abnormal innervation function at the back of the thigh and causing soreness. It can be treated in the hospital by means of discoscopic surgery. If you have soreness at the back of the thigh, you should go to the hospital in time and choose the appropriate treatment under the doctor’s guidance.