Cystometry is a test that measures the pressure inside of the bladder to see how well the bladder is working. Cystometry is done when a muscle or nerve problem may be causing problems with how well the bladder holds or releases urine.
Urination is a complex process. As the bladder fills, nerves in the bladder wall send a message to the spinal cord and brain that you need to urinate. In response, your spinal cord sends a signal for the bladder to contract (voiding reflex). When you hold in your urine, your brain is overriding this reflex. When you allow the reflex to occur, urination occurs. A problem affecting this nerve pathway or the muscles of the bladder wall can cause bladder dysfunction.
During cystometry, your bladder is filled with water or gas to measure its ability to hold in and push out the water or gas. Medicine may also be given to see whether your bladder contracts or relaxes normally in response to the medicine. A small tube (catheter) can be placed in your rectum to measure pressure as the bladder fills. A small pad or needle may be placed near your anus to measure muscle function in this area.
Why It Is Done
Cystometry is done to:
- Find the cause of problems with the bladder or the muscle that holds urine in the bladder (bladder sphincter). Problems in one or both of these areas may cause uncontrolled urine leakage, an urgent feeling that you have to urinate, or a weak urine stream.
- Measure how much urine your bladder can store and how much urine remains in your bladder after you feel you have completely emptied it (residual volume).
- Help you and your doctor make decisions about how to treat your urinary symptoms.
- See how well the bladder works in people with progressive neurological diseases, such as multiple sclerosis.
How To Prepare
Tell your doctor if you:
- Are taking any medicines. Some medicines and herbal supplements can affect bladder function.
- Are or might be pregnant.
- Have symptoms of a urinary tract infection, such as pain or burning with urination, foul-smelling or cloudy urine, or an urge to urinate more often than usual.
Talk to your doctor about any concerns you have regarding the need for the test, its risks, how it will be done, or what the results will mean. To help you understand the importance of this test, fill out the medical test information form(What is a PDF document?).