Urodynamic testing

About urodynamic testing

Urodynamic testing looks at how well your bladder stores and gets rid of urine. It can help to find out what is causing any problems you have with your bladder, such as urinary incontinence. If you have difficulty passing urine (urinary obstruction), it can also help to find out what’s causing this.

There are a number of different types of urodynamic tests, ranging from simple observation to precise measurements using sophisticated equipment. Your health professional will explain what type of urodynamic test is suitable for you.

Urodynamic testing measures how long it takes for your bladder to empty and whether the flow of urine out of your bladder is even, or if it stops and starts. The test will also measure how well your bladder contracts to start the flow of urine and how much pressure there is in your bladder and urethra (the tube that carries urine from your bladder and out through your penis, if you are a man, or vulva, if you are a woman).

These tests are usually done when the main cause of your symptoms isn’t known, or where there may be a several causes to your bladder problems. The tests can also be useful for people with neurological conditions, such as Parkinson’s disease, or if you’re having repeat surgery for a lower urinary tract condition.

What are the alternatives to urodynamic testing?

If you have other symptoms as well as urinary incontinence, your doctor may suggest other tests. These may include a cystoscopy, where your doctor looks inside your bladder using a thin, flexible camera, or imaging tests such as an X-ray or CT scan.

Urodynamic testing is usually only done if there is no obvious cause of your bladder problems.

Preparing for urodynamic testing

Your health professional will explain how to prepare for your procedure. For example, he or she may ask you to keep a record of how much you drink, and how much urine you pass and when, for the three days before your appointment. Keeping a urinary diary will help your health professional to understand your bladder problem.

If you’re taking medicines to treat a bladder problem, you may be asked to stop taking these before the tests. Your health professional or doctor will tell you which medicines to stop and when to stop them.

Urodynamic testing is routinely done as an outpatient procedure. This means you will have the test and go home the same day.

You can eat and drink as usual before having urodynamic testing. You may be asked to come to your appointment with a full bladder.

At the hospital your health professional may test your urine for an infection. If you have an infection (known as a urinary tract infection) the test will be cancelled and you will need to have it after your infection has gone. It’s important to delay the test as this will help to protect you against possible complications. You may be given antibiotics to clear the infection.

Your health professional will discuss with you what will happen before, during and after your procedure, and any pain you might have. This is your opportunity to understand what will happen, and you can help yourself by preparing questions to ask about the risks, benefits and any alternatives to the procedure. This will help you to be informed, so you can give your consent for the procedure to go ahead, which you may be asked to do by signing a consent form.

What happens during urodynamic testing?

Urodynamic testing usually takes between 15 and 30 minutes but this will depend on the exact type of urodynamic test that you have – ask your health professional how long it will take for your test.

You will need to take off your clothes from the waist down and put on a hospital gown. You will then lie down on a couch.

In a common type of urodynamic test called a cystometrogram, your health professional will pass one or two fine tubes called catheters into your bladder through your urethra. He or she will also put a catheter into your rectum (back passage). You may find this slightly uncomfortable but it shouldn’t be painful. Your health professional may put a local anaesthetic gel onto your skin around the entrance of your urethra before he or she puts the catheter in. This will help to make the procedure more comfortable. You may feel like you want to pass urine as the catheter is put in.

Your health professional will put fluid into your bladder through the catheter. A sensor on the end of the catheter will measure the pressure inside your bladder as it fills. The catheter inside your rectum will measure the pressure in your abdomen (tummy).

When your bladder is full, you will be asked to stand up and cough. You will be asked to use a commode and empty your bladder. The commode will have a flow meter in it, which will measure the flow of urine as you empty your bladder. When the test is over, your health professional will take the catheters out.

You may also have an X-ray or ultrasound of your bladder during the test.

What to expect afterwards

You will usually be able to go home when you feel ready. You can drive if you want to.

Your health professional may discuss the results of your test with you immediately afterwards or you may be given a date for a follow-up appointment. A report will be sent to the doctor who requested your test.

If your test doesn’t pick up any results, you may be booked in for an ambulatory urodynamics test – your health professional will discuss this with you. See our frequently asked questions for more information.

Recovering from urodynamic testing

You should be able to go back to your usual day-to-day activities straight away.

After your appointment, drink enough fluids, particularly for the first two days as this will help to reduce any discomfort.

You may be prescribed an antibiotic to reduce your risk of an infection. See your GP if you develop any symptoms of a urinary infection, which include:

  • pain in your lower abdomen or back
  • cloudy, smelly urine
  • passing urine frequently or needing to pass urine urgently
  • a burning sensation when you pass urine
  • blood in your urine
  • feeling unwell with a fever
  • an inability to pass urine

What are the risks?

As with every procedure, there are some risks associated with urodynamic testing. We haven’t included the chance of these happening as they are specific to you and differ for every person. Ask your doctor or nurse to explain how these risks apply to you.

If the urodynamic test involves X-rays, you will be exposed to some X-ray radiation. The level of exposure is about the same as the background radiation that you would receive naturally from the environment over a few months or a year. If you’re pregnant, or think you may be pregnant, tell your doctor before your appointment as there is a risk the radiation may affect the development of your baby.


Side-effects are the unwanted but mostly temporary effects you may get after having the procedure.

The side-effects of urodynamic testing include:

  • discomfort in the area where a catheter was put in – this should get better after a few hours
  • mild stinging when you pass urine
  • blood in your urine


Complications are when problems occur during or after the procedure. Complications of urodynamic testing are uncommon but can include a urine infection.

Should I take antibiotics to prevent a urine infection after the test?


During urodynamic testing, a catheter is put into your bladder. This can increase your risk of developing a urine infection. However, this risk is small so you won’t necessarily be asked to take antibiotics.


During urodynamic testing, fine tubes (catheters) are inserted into your body. When something is inserted into your body from outside, there is a risk of infection.

However, this risk is small and most people won't need to take antibiotics to prevent an infection. After your appointment, it's important to drink enough fluids each day for at least two days. This will help to 'flush out' your bladder.

If you develop any signs of an infection, such as cloudy, smelly urine, passing urine frequently or urgently, or a fever, see your GP.

My doctor suggested ambulatory urodynamic tests. What are these?


Ambulatory urodynamic tests are used to see how well your bladder stores and gets rid of urine when you’re going about your day-to-day life. The monitoring equipment for the test is portable, which means the sensors will record how and when you pass urine naturally.


Like other urodynamic testing, ambulatory urodynamics looks at how well your bladder stores and gets rid of urine. However, rather than having the test in an outpatient department, ambulatory urodynamics allows you to go about your usual activities while the test is carried out. Ambulatory urodynamics is a very useful technique for showing symptoms over a period of time, or symptoms that may not have shown up during standard urodynamic tests.

Thin catheters with a sensor at the end will be put into your bladder and your rectum (back passage) and then connected to a small box, which you wear on your waist. When the catheters and the monitoring box are correctly fitted, you can leave the outpatients department for a few hours and go about your usual activities. Your bladder will fill and empty naturally and the sensors will record how and when you pass urine.

After your test, you will need to go back to the hospital to have the catheters removed.

What is video-urodynamics?


A video-urodynamic test uses a special dye (contrast medium) to fill your bladder. This will help your bladder to show up on an X-ray, which can help your doctor to diagnose certain bladder problems.


Video-urodynamics is similar to a standard urodynamic test but instead of putting water into your bladder during the test, a special dye (contrast medium) is used instead.

Your bladder, and the parts of your body around it, are difficult to see on X-ray images. A special dye called contrast dye is sometimes used during urodynamic tests to highlight your bladder and urethra (the tube that carries urine from your bladder and out through your penis, if you are a man or vulva, if you are a woman) and make them easier to see. This can help your doctor to diagnose certain bladder problems.

During a video-urodynamic test, the X-ray images will be taken when your bladder feels comfortably full of the dye.