What is cystometry?
Cystometry is a test used to look for problems with the filling and emptying of the
bladder. The bladder is part of the urinary tract. It’s a hollow muscular organ that
relaxes and expands to store urine.
Cystometry measures the amount of urine in the bladder. That figure is compared with
the bladder pressure and how full you think your bladder is. The result tells your
healthcare provider about muscle function, mechanics, and nerve response of the bladder
and urinary tract.
Normally, the bladder sends messages to the brain through nerve pathways when it needs
emptying. The spinal cord then sends a message to the bladder to contract and start
the reflex of urinating. Normally, you can override this reflex voluntarily to hold
and control his or her urine.
Some conditions may interfere with the muscular function or nerve pathways between
the bladder and the brain. These conditions may lead to loss of bladder control or
urinary blockage. Cystometry may be used to find the source of such problems.
Why might I need cystometry?
Cystometry may be recommended to check for problems of the bladder and urethra. Conditions
that may cause problems of the bladder and urethra may include:
- Neurogenic bladder dysfunction. Improper function of the bladder due to a problem in the nervous system, such as a
spinal cord tumor or injury.
- Spinal cord injury
- Multiple sclerosis. An unpredictable disease of the central nervous system that changes communication
between the brain and other parts of the body.
- Diabetes. A health problem that happens when the body is not able to use sugar for growth and
energy for daily activities. It can lead to nerve damage.
Problems in the urinary system can also be caused by aging, other illness, or injury.
Weak bladder muscles may result in not being able to empty your bladder completely.
This is called urinary retention. Weak muscles of the urinary tract and pelvis can
lead to loss of urine control. This is because the muscles cannot stay tight enough
to hold urine in the bladder. Or the bladder does not have enough support from the
pelvic muscles to stay in its proper position. Cystometry may be used to find the
cause of symptoms like these.
There may be other reasons for your healthcare provider to recommend cystometry.
What are the risks of cystometry?
Some complications of cystometry may include:
- Urinary tract infection
- Autonomic reflex (severe headache, increased blood pressure, lower heart rate, sweating
and flushing) in people who have a spinal cord injury or a spinal cord tumor
Cystometry should not be done in someone with a urinary tract infection.
There may be other risks depending on your specific medical condition. Be sure to
discuss any concerns with your healthcare provider before the procedure.
Straining with urination and certain medicines may affect the results of a cystometry
How do I get ready for cystometry?
- Your healthcare provider will explain the procedure and you can ask questions.
- You may be asked to sign a consent form that gives your permission to do the procedure.
Read the form carefully and ask questions if anything is not clear.
- Generally fasting (not eating) or limiting fluids is not needed.
- If you are pregnant or think you may be, tell your healthcare provider.
- Tell your healthcare provider if you are sensitive to or are allergic to any medicine,
latex, tape, and anesthesia.
- Make sure your healthcare provider has a list of all medicines (prescribed and over-the-counter),
herbs, vitamins, and supplements that you are taking.
- Tell your healthcare provider if you have a history of bleeding disorders or if you
are taking any anticoagulant (blood-thinning) medicines, aspirin, or other medicines
that affect blood clotting. You may need to stop these medicines before the procedure.
- Tell your healthcare provider if you think you may have a urinary tract infection.
Symptoms include frequent urination, pain or burning when passing urine, fever, and
urine that looks dark, cloudy, or reddish in color and smells bad.
- You may need to start an antibiotic a day or so before the procedure to help prevent
a urinary tract infection.
- People who have problems with constipation may need to use an enema before the procedure.
Based on your medical condition, your healthcare provider may ask for other specific
What happens during cystometry?
Cystometry may be done on an outpatient basis or during a hospital stay. Procedures
may vary depending on your condition and your healthcare provider's practices.
Generally, cystometry follows this process:
- You will need to remove your clothing, jewelry, or other objects that may interfere
with the procedure.
- If you are asked to remove your clothing, you will be given a gown to wear.
- You will be asked to empty your bladder as well as you can before starting.
- You will be positioned on your back on an exam table.
- A soft, flexible tube called a catheter will be put in through the urethra until it
reaches the bladder. You may have some discomfort when this is done.
- The amount of urine left in your bladder will be measured. (This is called residual
- Another catheter or pressure probe may be put into the rectum or vagina to measure
pressure in the belly. Or, electrodes may be stuck to your skin on either side of
the anal opening to measure muscle function.
- A small amount of room temperature fluid will be put through the catheter into the
bladder. Next, an equal amount of warmed fluid will be put in. You will be asked to
describe what you feel when this is done, such as warmth, the need to urinate, discomfort
or pain, or nausea.
- The fluid will be drained out through the catheter.
- The catheter will be connected to a measuring device called a cystometer (an instrument
that measures bladder pressure).
- Fluid or gas will be slowly put through the catheter into the bladder. You will be
asked to tell when you first feel the urge to urinate and when you feel like you must
urinate. Bladder pressure will be recorded during this time.
- When the bladder is completely full, you will be asked to empty your bladder while
pressure is being recorded. A portable commode chair will be available for you and
the catheters will stay in place.
- In some cases, medicine that can affect the bladder’s muscle tone may be given, and
the procedure will be repeated in 20 to 30 minutes.
- When all tests have been done, the catheter will be removed. The rectal probe or sticky
electrodes will also be removed.
- You may have discomfort during this procedure, such as flushing, sweating, nausea,
pain, bladder filling, and urgent need to urinate. Be sure to tell the healthcare
provider how you are feeling.
What happens after cystometry?
There is no special type of care needed after cystometry. You may go back to your
usual diet and activities unless your healthcare provider tells you otherwise.
You will be urged to drink extra fluids to dilute your urine and reduce urinary discomfort,
such as burning.
You may feel some urinary discomfort, but it should lessen over time. Warm sitz baths
or tub baths may help.
You may see blood in your urine after the procedure. The amount of blood will lessen
Your healthcare provider may have you take an antibiotic to prevent a urinary tract
Tell your healthcare provider to report any of the following:
- Fever and/or chills
- Belly pain
- Continued or increased blood in your urine
- Urine output is less than usual
You healthcare provider may give you other instructions after the procedure, depending
on your situation.
Before you agree to the test or the procedure make sure you know:
- The name of the test or procedure
- The reason you are having the test or procedure
- What results to expect and what they mean
- The risks and benefits of the test or procedure
- What the possible side effects or complications are
- When and where you are to have the test or procedure
- Who will do the test or procedure and what that person’s qualifications are
- What would happen if you did not have the test or procedure
- Any alternative tests or procedures to think about
- When and how will you get the results
- Who to call after the test or procedure if you have questions or problems
- How much will you have to pay for the test or procedure