Sudden back pain can be caused by the following causes: first, urinary stones, when the kidney stones are large and travel down through the narrowing of the ureter, stuck in the narrowing of the ureter, there can be sudden back pain, often colic, can be paroxysmal, can be radiated to the abdomen and the emergence of hematuria, this time to check the kidney ultrasound, CT and urine tests for early diagnosis and treatment. Second, renal vascular disease, when the arteries of the kidney are blocked due to thrombosis or embolism, there can be sudden back pain, often tearing pain, then we should check the renal angiography to diagnose and treat. Third, the rupture of kidney tumor, when the kidney tumor suddenly rupture can also have the symptom of sudden back pain, often colic or tear-like pain, then we should check the urography and MRI, ultrasound for early diagnosis and treatment.