Low back pain accompanied by bleeding in urine is usually caused by diseases such as ureteral stones, acute pyelonephritis, and kidney tumors. 1. Ureteral stones: when the stones are discharged from the kidney into the ureter, patients may experience strangulation-like pain, accompanied by symptoms of urinary urgency and frequency. If the stone causes mucous membrane damage, the phenomenon of blood in urine will be formed. 2. Acute pyelonephritis: due to infection caused by renal lesions, there may be pain in the lower back, and in severe cases, it may radiate to the surrounding area, and at the same time, the vascular permeability changes red blood cell exudation, forming hematuria. 3. Renal tumor: renal tumor invades the blood vessels of renal parenchyma to cause painful hematuria, when the bleeding is large, forming blood clot, discharged to the ureter, there may be renal colic similar to ureteral stone-like. 4. Kidney stones: Kidney stones are often associated with lumbar pain, and the degree of pain depends on the size and location of the stones; hematuria often occurs after the pain. When there is back pain and hematuria, it is recommended to consult a doctor in time, follow the doctor’s instructions for further examination, clarify the cause with the help of the doctor, and carry out targeted treatment or therapy.