The following are common causes of left-sided lumbar pain in women: a. Muscle strain: the most common cause of left-sided lumbar pain, most female patients like to cross their legs and sit in an improper posture, which can cause significant strain on the left-sided lumbar muscles, and patients will have clinical manifestations of left-sided lumbar pain and swelling, and clinical symptoms will soon be relieved after rest and correction of poor posture. Second, kidney stones, inflammation of the urinary system: all can lead to pain symptoms in the left side of the waist, the pain is usually intolerable during acute attacks, the patient needs to use strong analgesic drugs, which can relieve clinical symptoms. If the clinical manifestation of pain on the left side of the waist occurs, it is important to pay high attention and early examination and early treatment, and the symptoms will be relieved quickly after treatment.