Women with left-sided back pain may be caused by the following reasons: a. Inflammatory reaction in the left adnexal area, especially local inflammation of the fallopian tubes leading to a large amount of exudation, causing adhesions between the fallopian tubes and the posterior peritoneum, so there will be pain in the lower back, which will be relieved by active clinical anti-inflammatory treatment. Second, there is a relatively large tumor in the left adnexal area pressing on the posterior peritoneum and causing lumbar pain. Most of them can be diagnosed initially through ultrasound examination, and surgery is recommended if necessary. Third, it may be related to diseases of other departments, such as lumbar muscle strain or lumbar spine hyperplasia, which may lead to such symptoms.