Pelvic pain on both sides of the waist may be a symptom of lumbar spine disease, lumbar muscle strain, rheumatism and immunity disease. 1. Lumbar spine disease: herniated lumbar intervertebral discs, bulging and other abnormalities will stimulate the lumbar posterior longitudinal ligament, which in turn manifests the pelvic upper side of the waist on both sides of the pain. 2. Lumbar muscle strain: lumbar muscle strain due to the presence of aseptic inflammation in the corresponding area, which will lead to pain in the muscles around the waist, manifesting the pelvic pain on both sides of the waist, and the symptoms will worsen when overworked or cold. 3. Rheumatic immune disease: rheumatic immune disease such as ankylosing spondylitis, the chronic inflammation caused by it can also lead to pelvic pain on both sides of the waist. Pelvic pain can also be caused by other reasons. If the pain persists, it is recommended to consult a doctor in time to clarify the cause of the pain and treat the symptoms under the doctor’s guidance.