If blood accumulates in the bladder, it is recommended to go to the hospital for relevant examinations to clarify the possible causes: first, tumors of the kidney and ureter can cause blood accumulation in the bladder. This is often seen when the tumor breaks down and bleeds, the bleeding volume is relatively large and the blood mixed with urine flows into the bladder, forming a blood accumulation in the bladder, which can have a red urine color during urination and can even be accompanied by changes in blood clots. Secondly, kidney contusion, when the waist is more violent trauma, so that the kidney can appear to have contusion, laceration, or even rupture. The actual fact is that you can find a lot of people who are not able to get a good deal on a lot of things. Thirdly, men with prostate hyperplasia combined with chronic urinary retention can also cause there to be blood accumulation in the bladder. The ruptured blood vessels on the surface of the prostate gland bleed and accumulate within the bladder, and because the prostate enlargement has blocked the urethra, the blood and urine accumulation in the bladder cannot be discharged smoothly, and even blood clots in the bladder can be formed.