There are several reasons for the pain and soreness of the right side of the lower back in women: the first reason is lumbar muscle strain, which is commonly caused by long-term strain or bending over to hold things, sitting for a long time or catching a cold, and then there will be soreness and pain in the muscles of the lower back, especially when bending over. The second cause is kidney disease, such as kidney stones or kidney tumors, which may cause pain on one side of the waist, and CT, ultrasound or urography should be performed to further confirm whether the pain is caused by urinary tract diseases. The third reason is gynecological diseases, such as the patient wearing a birth control ring, which can also cause pain on one side of the back, or pelvic inflammatory disease and pelvic effusion, which can also lead to pain and soreness in the back. In case of acute onset of lumbar pain, an urgent ultrasound should be performed to check if the pain is caused by acute ovarian torsion, ectopic pregnancy or ovarian rupture, which is often accompanied by abdominal pain and symptoms of acute abdomen.