Left hip pain may be caused by physiological factors such as incorrect sitting posture, or it may be caused by pathologic reasons such as fatigue injury, pyriformis injury, or lumbar disc herniation. 1. Physiological factors: If the sitting posture is incorrect, resulting in long-term pressure on the left buttock, the above symptoms may occur. 2. Pathological causes: there are several muscle tissues attached to the left buttock such as gluteus maximus, gluteus medius, gluteus minimus, etc. People who often use their left leg to exert force may cause micro-injury of these muscle parts, and aseptic inflammation may occur, causing the symptoms of pain in the left buttock. The sciatic plexus runs along the lower edge of the pyriformis muscle, which innervates the sensation and movement of the buttocks as well as the lower limbs. If the left side of the pyriformis muscle is damaged due to infection or trauma, the left sciatic nerve may be caused to be compressed, and the above mentioned symptom may also occur; lumbar intervertebral disc herniation may cause compression of the spinal nerve roots or spinal nerves on the left side, and the symptom of left buttock pain may occur. There may be other causes of left hip pain, it is recommended to go to the hospital in time, improve the examination to clarify the cause of the disease, and then give targeted treatment or therapy under the guidance of the doctor.