Left buttock pain is considered to be caused by lumbar intervertebral disc herniation, gluteal myofasciitis, pyriformis syndrome and other reasons. 1. Lumbar intervertebral disc herniation: when patients with lumbar intervertebral disc herniation disease, lumbar vertebrae abnormally protruding may compress local nerve tissues, and when it involves the nerve tissues of the left buttocks, the symptom of left buttock pain will appear. 2. Gluteal muscle fasciitis: if the patient’s left buttock is exercising for a long time or wearing too little clothes, the local tissues will be cooled, resulting in spasm of the local fascial tissues of the gluteal muscle, which will cause the symptom of left buttock pain. 3. Piriformis syndrome: if the patient sits for a long time or the local tissue injury causes abnormal edema or adhesion of the piriformis muscle, when the secreted inflammatory factor stimulates the sciatic nerve, the symptom of left buttock pain may appear. It is recommended to go to the hospital in time for examination and diagnosis, and carry out targeted treatment under the guidance of professional physicians to avoid aggravation of the condition.