Test Overview
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.