Sudden pain in the back is commonly associated with urinary stones, acute lumbar sprains, or disorders of the small joints of the lumbar vertebrae or lumbar disc herniation. Urinary stones are usually colicky, and the pain will be more obvious when knocking on the area of back pain, sometimes accompanied by pain in urination or nausea, vomiting and other symptoms. Small joint disorders of the lumbar spine, acute lumbar sprain or lumbar disc herniation, sometimes there is no obvious special external triggers, get up when the lumbar spine too much force or twisting the waist when flashed, or even obvious sneezing, because the abdominal pressure is too much change can also be caused. And this type of pain need to go to the orthopedic department of the hospital to let the doctor check, if necessary, do lumbar spine CT examination, comprehensive judgment of the specific characteristics of the lesion. If the pain is obvious, you should go to the hospital immediately. If urinary stones damage the urethra, it can be troublesome.