What is a flow rate test?
A flow rate test measures how fast you can pee. This test helps Doctors understand how well your bladder and your urethra (the tube that carries pee out of your body) are working.
What are the benefits of having a flow rate test?
This test helps doctors find out if there are any blockages or problems with your bladder. It’s a simple and painless way to check how well your urinary system is working.
What are the risks of having a flow rate test?
There is a small risk that in some patients the sodium (salt) level in the body may become very low from drinking a lot of water. If you start to feel sick please stop drinking.
Are there any alternatives to a flow rate test?
An alternative to this test is a test called urodynamics, but this is not suitable for everyone. It involves a small tube (catheter) being passed into the bladder which is then filled and your bladder pressure recorded.
Another alternative is not having the test, however this may prevent doctors from making a diagnosis.
How do I prepare for a flow rate test?
You can eat and drink as normal before your appointment, but we will need you to have a comfortably full bladder for the test so suggest that you drink 1 litre (2 pints) of water 1 hour before your appointment. You can continue drinking at the hospital if needed.
When you arrive for your appointment please do not pass urine until you have spoken to the nurse. If you do not feel ready to do the test when you arrive you will be given a drink.
Please tell the nurse if you:
- have a history of low sodium
- take water tablets
- have kidney disease
What happens when I arrive for my appointment?
Plan to arrive at the clinic with enough time to register and settle before your scheduled appointment. Tell reception staff that you are prepared for the flow rate test.
During the test
During your appointment you will be taken to a private room and asked to pass urine (pee) into a special machine either on a special toilet or through a funnel which measures how fast and the amount that is passed. After this, if you need to have a bladder scan, you will be asked to lie down on a bed or couch.
Some jelly will be applied to your tummy and an ultrasound probe will be passed over it to produce a picture of your bladder on a screen. This will show how much urine remains in your bladder after you have completely emptied it.
After the test
You will be able to go home and return to your normal activities straight after the test. The nurse or doctor may speak to you about the results before you leave or may write to you with the results or offer you a follow-up appointment.
How to contact us
Please contact your urologist’s secretary if you have any questions or concerns about this test.
You can contact them by calling the main switchboard on 01709 820000 and asking for them.
Further information
For more information about bladder problems:
- Bladder and Bowel Foundation
Helpline: 0845 345 0165 - British Association of Urological Surgeons