For the urinary system to do its job, muscles and nerves must work together to hold urine in the bladder and then release it at the right time. Nerves carry messages from the bladder to the brain to let it know when the bladder is full. They also carry messages from the brain to the bladder, telling muscles either to tighten or release. A nerve problem might affect your bladder control if the nerves that are supposed to carry messages between the brain and the bladder do not work properly.
What bladder control problems does nerve damage cause?
Nerves that work poorly can lead to three different kinds of bladder control problems.
Diagram of a brain, spinal cord, and bladder. Labels point to the brain, spinal cord, bladder, urethra, and sphincter muscles. An additional label explains that the brain and spinal cord make up the central nervous system. Arrows pointing from the spinal cord to the bladder and sphincter muscles represent nerve signals.
Nerves carry signals from the brain to the bladder and sphincter.
Damaged nerves may send signals to the bladder at the wrong time, causing its muscles to squeeze without warning. The symptoms of overactive bladder include
Poor control of sphincter muscles. Sphincter muscles surround the urethra and keep it closed to hold urine in the bladder. If the nerves to the sphincter muscles are damaged, the muscles may become loose and allow leakage or stay tight when you are trying to release urine.
For some people, nerve damage means their bladder muscles do not get the message that it is time to release urine or are too weak to completely empty the bladder. If the bladder becomes too full, urine may back up and the increasing pressure may damage the kidneys. Or urine that stays too long may lead to an infection in the kidneys or bladder. Urine retention may also lead to overflow incontinence.