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Why a urodynamic test is done

A urodynamic test is done to get more information about your urination cycle and how your bladder muscles work. There are several urodynamic tests which your doctor may use to better understand your condition. These include uroflowmetry and cystometry.

Overactive bladder symptoms can point to other conditions. Part of the diagnosis is ruling out other possible explanations for the symptoms, such as urinary infection or diabetes.


The tests usually don’t need a lot of preparation, but it is important to check in advance with a urine sample that no infection is present. Also check if you need to stop any medicine intake. The tests take about 30 minutes to complete.

If you have an infection, you should be treated with antibiotics before the urodynamic study can take place. Please bring the results of the urinary test to your appointment.

How is the urodynamic test done?

Urine flow test

  • Your health care provider may first start with the urine flow test.
  • You’re given some privacy and asked to urinate in a special toilet. This toilet measures the force and flow of your urine (See Fig.1).
  • After that, an ultrasound of your bladder is done to see how well it emptied.


  • If you also need cystometry, you will be in a lying, seating or standing position.
  • With a local anaesthetic, a catheter is inserted in your urethra. Another catheter is placed in your rectum.
  • Both catheters measure the pressure in your bladder and your abdomen.
  • Sensors on your abdomen monitor the activity of the pelvic muscles.
  • Using the catheter, the doctor will fill your bladder with a sterile fluid and ask you to cough or bear down to test your bladder reaction.
  • The doctor checks if there is any leakage of urine and if you feel the need to urinate.
  • When your bladder is completely full, you are asked to empty your bladder while pressure is being recorded. At the end of the cystometry test, the catheters and sensors are removed.
Fig. 1: A common type of uroflowmetry container for men and women.
Fig. 1: A common type of uroflowmetry container for men and women.

Sudden high blood pressure (Autonomic Dysreflexia)

Some patients have a risk of sudden high blood pressure (autonomic dysreflexia) during urodynamic testing. This risk has to be managed. It is a sudden and exaggerated automatic response to various stimuli in patients with spinal cord injury or spinal dysfunction. The stimulus can be a full bladder or bowel. It can also result from sexual stimulation or pain, for example, an infected toenail or a pressure sore. Sudden high blood pressure can be life-threatening if not properly managed.

The procedure

This animation shows how a typical urodynamic test is performed.


Right after the tests are done, your doctor will discuss the results with you, and any further treatment you may need. Drink plenty of liquids after the tests to reduce discomfort while urinating.

Bladder diary

Your doctor may ask you to keep a bladder diary. You should note how much fluid you drink, how often you urinate, and how much urine you produce during the day and at night. The bladder diary is important because it helps your doctor understand your symptoms better, and your treatment can be adjusted if necessary. You can print a bladder diary here.

The information does not take into account your individual medical situation. If you have questions or concerns about your health, please contact your doctor. No information can replace a personal conversation with your doctor.

This EAU Patient Information project is supported by an educational grant from Astellas.

This information was produced by the European Association of Urology (EAU) Patient Information Working Group.
Prof. Dr. T. Bach, Dr. G. Patruno, Dr. A. Prouza.

The content is written independently of the sponsor and judged free of any conflict of interest.