Back pain can be caused by lumbar muscle strain, lumbar tumor, kidney disease, etc. General treatment, physical therapy, medication and surgery are feasible. 1. Lumbar muscle strain: Lumbar muscle strain can occur in the local aseptic inflammation, stimulated by the inflammation can appear in the back of the lumbar distension and discomfort symptoms. Attention should be paid to lumbar rest, reduce activities, feasible lumbar hot compresses, massage, massage and other treatments, and oral ibuprofen and other non-steroidal analgesic and anti-inflammatory drugs as prescribed by the doctor. 2. Lumbar tumor: when tumor occurs in lumbar soft tissues, it can cause distension and pain in posterior lumbar area due to tumor invasion and compression of surrounding tissues. You should consult doctor in time to clarify the situation of the tumor, and usually need to perform surgical resection of the tumor under the guidance of specialists according to the condition of the tumor. 3. Kidney disease: When there are large cysts or tumors in the kidney, they can compress the surrounding tissues and cause swelling and pain in the lower back. If simple cysts are not combined with other symptoms, regular checkups can be conducted to observe the changes of the condition; if they are combined with infections or larger cysts, surgical treatment is needed. Kidney tumors should be treated with surgery under the guidance of doctor according to the condition. When there is swelling and pain in the lower back, one should consult a doctor in time and take appropriate treatments under the guidance of specialists, which will help to alleviate the discomfort as soon as possible.