What is the harm of holding urine for a long time

The harm of holding urine for a long time to the body is relatively large. First, it will cause damage to the bladder. Holding urine for a long time will make the bladder in high pressure for a long time, which is easy to cause cystitis. Secondly, holding urine for a long time may cause retrograde urine, leading to kidney and ureter infection. Serious may affect kidney function.