Having a flow test
Date issued: November 2021
Review date: November 2023
Ref: A-466 v2
PDF: Having a flow test final November 2021 v2.pdf [pdf] 66KB
What is a flow test?
This test records the rate at which you pass urine and the amount you pass. It is carried out to assess the changes you have experienced in your usual flow of urine. To record this information, you will be asked to pass urine into a special machine, within a private room.
What is a bladder scan?
After your flow rate test, it will be necessary to scan your abdomen to determine whether you have emptied your bladder fully or retained some urine. This is a painless procedure. A small amount of gel is put on your abdomen and an ultrasound probe is used to obtain a picture of your bladder onto a screen. Any residual urine is shown on the screen and the volume is calculated.
Are there any risks involved?
There are no side effects to either of these tests and you can resume your normal activities immediately afterwards.
On the day of the procedure
You can eat and drink as normal before your appointment.
For an accurate flow rate recording to be achieved, we require you to have a (comfortably) full bladder on arrival and not to pass urine until you have spoken to a nurse.
If you pass less than 150mls of urine the test results may not be able to be analysed, which may mean that you will need to repeat the test. Please be prepared that you may need to stay for a few hours so please bring something to do i.e. book or magazine to read.
If possible we would like you to drink a few cups of fluid (no more than 500 mls) before attending the clinic. If you do not feel ready to do the test when you arrive at the clinic, there is a water machine available. The length of time you need to stay in the department depends upon when you are able to perform a satisfactory flow test.
**Arriving at the department with a full bladder will reduce your waiting time, although if you experience problems such as frequency or urgency, we understand it may be difficult for you to travel with a full bladder.**
What happens after the procedure?
After your flow rate test and scan, the nurse or doctor will speak to you or write to you about the results and any subsequent treatment and/or any necessary further appointments.
