Sudden back pain may be caused by the following reasons: 1, small joint disorders, especially in the elderly, due to the elderly lumbar spine serious degeneration, ligament laxity, prone to small joint disorders, although there is no trauma, there can be sudden back pain, to carry out the relevant examination to exclude other diseases. 2, kidney, ureteral stones, when the kidney stones fall down to the ureter, there will be ureteral stones When the kidney stone falls down to the ureter, the ureteral stone will appear, leading to sudden pain in the waist, then we should carry out ultrasound of the waist and urine test to further confirm the diagnosis. 3, vascular embolism, for example, the embolism of the renal artery will lead to sudden pain in the waist, which is easy to confuse with the renal stone and other diseases, and we need to carry out the angiography to confirm the diagnosis. 4, rupture of the renal tumor, when there is a rupture of the tumor of the kidney, it will also appear sudden pain in the waist, then we need to combine with the history as well as the CT and nuclear magnetic examination to further investigate the pain in the waist. In this case, it should be combined with medical history and relevant CT and MRI examinations to further confirm the diagnosis.