Neurogenic bladder is the loss of normal bladder function caused by damage to part of the nervous system.

What is going on in the body?

The nervous system controls two processes in the lower urinary tract to maintain continence. One is relaxing the bladder wall so that it can fill with urine until the person wants to urinate. At that point, the bladder wall contracts. The other is the urinary sphincter. The sphincter acts like a valve at the opening of the bladder. It contracts to hold urine in the bladder. The person relaxes it to release urine when the bladder contracts. A person with urinary incontinence from a neurogenic bladder has leakage of urine because the nervous system that controls the bladder or the sphincter is not working properly. Either the bladder is unable to relax or the sphincter is unable to close.

What are the causes and risks of the condition?

Injury to the brain and spinal cord above the waist level produces a bladder that is unable to relax, or one that contracts too frequently. Such injuries include stroke, spinal cord injury, head injury and multiple sclerosis.

A weak or inactive urinary sphincter is caused by injuries to the nerves that go from the spinal cord to the sphincter. These injuries happen with trauma or surgery, or a person may be born with them.