One side of the buttock pain is mainly associated with unilateral sciatic nerve compression or excessive pulling stimulation, may be caused by the pear-shaped muscle syndrome, may also be caused by lumbar spine disease. 1. Pear-shaped muscle syndrome: pear-shaped muscle syndrome is mainly related to its anatomical position, the pear-shaped muscle belongs to a group of hip external rotator muscle group, below which there is a sciatic nerve penetration, when the pear-shaped muscle injury or chronic inflammation, it is easy to cause the sciatic nerve compression, the symptom of hip pain on one side. 2. Lumbar spine disease: the above symptoms of lumbar spine disease may be due to lumbar spine degenerative lesions caused by lumbar disc herniation; it may also be due to the soft tissue around the vertebrae to reduce the holding force of the lumbar vertebrae; it may also be due to degenerative diseases, congenital spinal developmental abnormalities caused by spinal stenosis and other reasons. Sometimes the symptoms of buttock pain on one side alone cannot accurately determine the cause, but also need to be combined with the characteristics of the medical history, other test results to make an accurate judgment, it is recommended to clarify the cause of the disease under the guidance of a doctor and targeted treatment.