Occasional pain on both sides of the lumbar crotch tip may be caused by sacroiliac arthritis, lumbar intervertebral disc herniation, lumbar muscle strain and other diseases. 1. Sacroiliac arthritis: this disease is due to the inflammatory reaction of bilateral and unilateral sacroiliac joints, mainly due to the degeneration of joint function, mostly occurring in young adults, with the main symptoms of lumbar pain and joint mobility disorders. 2. Lumbar disc herniation: Lumbar disc herniation is mainly due to degenerative changes in various parts of the lumbar disc, which can lead to irritation or compression of the adjacent nerve roots under external factors, thus producing lumbar pain. 3. Lumbar muscle strain: mainly lumbar muscles and their attachment points of fascia, periosteum of chronic injury inflammation, the main clinical symptoms of lumbar, lumbosacral distension and pain, and labor will be aggravated, and at rest to get relief. Occasionally both sides of the lumbar crotch tip at the same time pain, it is recommended to go to the hospital for examination, identify the causes of timely treatment.