How Long Does a Urodynamic Test Take?

How long does a urodynamic test take?

A urodynamic test usually takes about 30 minutes.
A urodynamic test usually takes about 30 minutes.

The entire urodynamic test usually takes about 30 minutes. If the entire series of tests need to be performed, it may take up to one hour or more. The duration may differ among medical centers or hospitals. In children, the test may take longer—more than an hour.

There are many types of urodynamic tests. Your doctor may recommend you go for any one or two of the tests. They will decide the type of urodynamic test you should have based on your medical history, physical exam and symptoms.

How do I prepare for a urodynamic test?

Most of these tests do not require the patient take any special precautions, such as fasting before the test. However, the doctor may instruct the patient to discontinue certain medicines for a few tests. The patient will usually be asked to consume a lot of water until they feel like peeing.

What is a urodynamic test and how is it done?

A urodynamic test is also known as urodynamic series (UDS) because it is not just one test but a series of tests. The test checks for the efficiency of the bladder, sphincters and urethra to hold and release urine and check if there is any leakage. The structures together are known as the lower urinary tract. 

Urodynamic tests make use of various equipment and machines to check the different aspects of the urination process. These tests include

Cystometry: This involves inserting a long tube known as a urinary catheter into the urethra and sometimes into the rectum as well. The catheter contains a pressure-measuring device known as a manometer. The patient will be asked to empty the bladder followed by filling the bladder with warm water through the catheter. 

Leak point pressure measurement: This test is done during the cystometry test wherein the pressure at the point of leakage is checked. It measures the amount of abdominal pressure required to cause leakage of urine from the bladder/urethra.

Postvoid residual measurement: The doctor inserts the catheter through the urethra up into the bladder to remove and measure the amount of remaining urine.

Electromyography: This test uses electrode patches known as sensors, placed on the skin near the urethra, or a catheter inserted through the urethra. These sensors record the activity of the nerves and muscles. 

Uroflowmetry: The patient will be asked to urinate privately into a special toilet or funnel that has a container for collecting the urine and a measuring scale. The scale is connected to a computer that will measure the amount and flow of the urine.

Video urodynamic tests: While the patient empties their bladder and it gets filled with water via a catheter inserted into the urethra, the entire process is recorded on an X-ray or ultrasound machine.

The catheter and the sensors will be removed as soon as the measurements are recorded.

What should I expect after urodynamic tests?

After urodynamic tests, the patient can expect to experience mild discomfort while passing urine. This may last for a few hours. To relieve it, the doctor may advise the patient to

  • Drink an eight-ounce glass of water every half-hour for a few hours.
  • Take a warm bath.
  • Hold a warm, damp washcloth over the urethral opening.

There is also a slight possibility of getting a urinary tract infection whose signs and symptoms are

Do not worry. The doctor will prescribe a short course of antibiotics to fight off the infection. The patient should call the doctor right away if they experience problems such as blood in their urine.

The patient can expect to get results of some of the tests such as cystometry and uroflowmetry immediately after the test. Results of electromyography and video urodynamic tests may take a few days.


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