When the bladder becomes full, a reflex reaction occurs to empty the bladder. The sphincter muscle relaxes to open the bladder outlet and the bladder wall contracts to squeeze out the urine. In infants, this reflex occurs automatically. After toilet training, we are able to control the reflex so the bladder empties only when we "give it permission."
If the bladder does not empty fully, urine may build up and cause the bladder to become enlarged. The distended bladder may leak, a condition called overflow incontinence.
The treatment depends on the cause, which generally fall into two categories:
- blockage of the bladder outlet
- failure of the bladder to contract enough to push out the urine
Find out more about this book:Harvard Medical School Better Bladder and Bowel Control