Sudden back pain can not stand straight and bending pain can be caused by the lumbar spine and joint synovial inlay, acute lumbar sprain, urinary stones and other factors. 1. Lumbar spine and joint synovial embedded: bending action and lumbar twist, and violently straighten the waist, can lead to lumbar vertebrae and synovial joints of the synovial embedded, can cause sudden severe pain in the lumbar region, resulting in the inability to bend, need to consult a doctor in a timely manner, the line of manipulation of reset therapy to lift the synovial embedded. 2. Acute lumbar sprain: lifting and carrying heavy objects due to excessive lumbar force, which can lead to lumbar muscle overload and strains, localized swelling, bruising and other manifestations, there can be obvious pain. Need to timely bed rest, reduce local activities, oral ibuprofen pain treatment as prescribed by the doctor, can be applied to the bruise cream and other drugs to promote the recovery of the injury. 3. Urinary stones: kidney stones detached down through the ureter, the stones can produce irritation of the ureteral wall and intense pain in the lower back symptoms, need to consult a urological ultrasound and abdominopelvic CT and other tests to clarify the size of the stones, can be more water activities, extracorporeal shock wave lithotripsy and surgical lithotripsy and other treatments. There are many reasons for back pain, if it is difficult to relieve the pain, you need to consult a doctor in a timely manner, under the guidance of specialists to actively carry out appropriate treatment, which will help to relieve the symptoms of back pain as soon as possible.