Sudden lumbar pain may have the following causes: first, acute lumbar sprain, when the muscles of the lumbar region are sprained, there can be sudden lumbar pain, often with a clear history of lumbar sprain, then the relevant examination and examination to exclude other diseases for diagnosis; second, small joint disorders of the lumbar spine, when there is a history of sprain and trauma to the lumbar region, there can be misalignment and disorders of small joints, which can lead to sudden lumbar pain, then When a kidney stone travels downward and gets stuck in the ureteral stenosis, sudden lumbar pain can occur, such as colic, which can be accompanied by reflex pain in the abdomen. Fourth, blockage of the kidney blood vessels, when there is a sudden blockage of the kidney arteries, such as thrombosis or embolism, there can be sudden back pain, often tearing pain, then angiography should be performed for diagnosis and treatment.