Post-Void Residual Urine Test

What is a post-void residual urine test?

The amount of urine that remains in your bladder after you urinate (pee) is called post-void residual (PVR). A post-void residual urine test measures the amount of urine left in your bladder.

Ideally, when you go to the bathroom, your bladder should empty completely. But sometimes, urine stays in the bladder even after you think you’ve emptied it. The PVR test can tell your healthcare provider if you’ve completely emptied your bladder. A small amount of residual urine is generally ok, but large amounts can be concerning for urinary retention.

When might my doctor order a post-void residual urine test?

Your healthcare provider may recommend a PVR test if you have any symptoms of urinary retention. Urinary retention can be due to a number of medical problems, such as:

• Blockage in your urinary tract.
• Enlarged prostate.
• Medication side effects.
• Narrowed urethra (the tube through which urine flows).
• Neurogenic bladder.

Not emptying your bladder all the way can lead to symptoms and complications, including:

• Frequent urination.
• Urine leakage (incontinence).
• Urinary tract infections (UTI).
• Kidney damage.
• Bladder stones.

How do I prepare for a post-void residual urine test?

Just before the test, your provider will ask you to go to the bathroom and empty your bladder as completely as possible. To accurately measure PVR, you should have the test immediately after you urinate.

What are the types of PVR testing?

Your provider can use different methods to measure post-void residual volume. The two most common methods are ultrasound or bladder catheterization.

What happens during an ultrasound PVR test?

This noninvasive test doesn’t require any anesthesia. During an ultrasound, you lie still on a table.

Your provider may choose one of these types of ultrasound to measure the post-void residual:

• Bladder ultrasound or bladder scan: The ultrasound technician applies a special gel over your abdomen (belly) then passes the ultrasound probe over the area. The ultrasound shows images of your bladder on a screen nearby. By looking at these images, your provider can calculate the amount of urine that remains in your bladder.
• Vaginal ultrasound: For this type of ultrasound, the technician applies the special gel to the ultrasound probe. They then insert the probe into your vagina. The probe produces images of your bladder and measures the amount of urine in it.

What happens during bladder catheterization to measure PVR?

For this procedure, your provider gives you a local anesthetic (a numbing agent). Then the provider inserts a thin tube called a catheter through your urethra and into your bladder. Any urine left in your bladder drains out through the catheter. The provider then measures the amount that drains out.

What happens after a post-void residual test?

After an ultrasound, you can wipe any remaining gel off your skin, get dressed and go home.

After bladder catheterization, your provider gently removes the catheter from your urethra. You can go home after the procedure. You may feel slight discomfort as the anesthesia wears off. Drinking lots of water, and urinating several times, can help. Your provider may prescribe an antibiotic to prevent urinary tract infection.

If you have signs of urinary retention — meaning high residual urine volume — your provider will discuss ways to address this. Options could include a catheter (a tube that drains your bladder), medications and/or surgery.

What are the risks of having a post-void residual test?

Ultrasound doesn’t have any known risks. After bladder catheterization, there is a slight risk of getting a urinary tract infection or blood in your urine. Your provider may prescribe antibiotics to reduce the risk of infection.

When will I know the results of the PVR test?

Ask your healthcare team when you can expect results. For some tests, your provider may share the results immediately. For others, it may take a couple of days for your provider to analyze the results.

When should I call my doctor?

Call your healthcare provider if you notice:

• Abdominal pain or swelling.
• Inability to urinate.
• Pain when urinating.
• Signs of a urinary tract infection.

A note from Cleveland Clinic

Your healthcare provider can use the information from a post-void residual urine test to help diagnose what’s causing you to retain urine. Typically, you can manage most conditions that cause post-void residual with medication, surgery or other treatments.