Diagnostic Test
Flow Rate Test & Bladder Scan
A quick, non-invasive combined test to measure the speed of your urine flow and check if any fluid remains in your bladder. Ideal for checking prostate or bladder health.
Key Takeaways
- A quick, non-invasive combined test to measure the speed of your urine flow and check if any fluid remains in your bladder. Ideal for checking prostate or bladder health.
- We offer specialist interpretation and related treatments. Book a consultation to discuss your options.
Overview
About Flow Rate Test & Bladder Scan
This is a straightforward, two-in-one assessment used to evaluate how well your lower urinary tract is working. It combines a urine flow rate test with a post-void bladder scan.
First, you pass urine into a specialized toilet called a flow meter, which automatically measures how much urine leaves your body and how fast it flows. Immediately afterwards, a small, portable ultrasound scanner is placed gently on your lower tummy to measure if any urine has been left behind. Because it uses sound waves to check your bladder, there is absolutely no radiation involved.
Test Information
Understanding Your Test
A detailed guide to your diagnostic procedure — from essential preparation and the purpose of the test to safety considerations and what to expect during the process.
The entire combined test takes place in a private clinic room and is completely straightforward.
When you feel a normal, clear urge to pee, you will be shown to a private toilet containing the flow meter machine. You simply pass urine into the funneled device exactly as you would normally do at home. Try not to press, strain, or rush—just let it flow naturally. The machine will instantly create a digital chart showing your flow pattern.
As soon as you have finished, you will lie down comfortably on your back on a clinical examination couch. The nurse or specialist will apply a small amount of warm, clear gel to your lower abdomen. They will then sweep a small, handheld ultrasound probe across your skin for a few seconds. The scanner calculates the remaining fluid volume instantly. Once wiped clean, you can get dressed and resume your day.
The combined test is completely painless and non-invasive. There are no needles, injections, or catheters used.
The ultrasound gel placed on your tummy can feel slightly cool or wet for a few seconds, but it is wiped away cleanly with a tissue right after the scan. The only mild discomfort you might feel is the natural sensation of needing a pee before the test begins.
Your GP or urology specialist will usually recommend this combined test if you are experiencing lower urinary tract symptoms (LUTS). These symptoms might include a weak or hesitant urine stream, having to strain to pee, a sudden urgency to go, or a persistent feeling that your bladder hasn't completely emptied.
According to UK national guidelines, it is an essential first-line assessment tool. For men, it plays a vital role in checking whether an enlarged prostate gland is physically blocking the flow of urine. For women and men alike, it helps specialists see whether urinary issues are caused by an obstruction or a weakness in the bladder muscle itself.
At a glance
Preparation required
- Arrive with a comfortably full bladder: The most important preparation is ensuring you are ready to pee when you arrive at the clinic.
- Drink around 1 to 1.5 litres of water in the 2 hours leading up to your appointment.
- Do not overfill your bladder to the point of pain or extreme discomfort. If your bladder is painfully overstretched, it can temporarily weaken the muscle and give an inaccurate, artificially low flow reading.
- Wear loose, comfortable clothing that is easy to adjust around your waist.
Risks or considerations
- There are zero physical risks or medical side effects associated with this test.
- The "shy bladder" factor: It is incredibly common for patients to feel a bit anxious or self-conscious about peeing "on demand" in a clinical setting, which can sometimes cause your flow to stop or hesitate.
What it can help diagnose
- Bladder outlet obstruction, very commonly caused by an enlarged prostate (Benign Prostatic Hyperplasia - BPH) or a narrowing of the urethra
- A weak or underactive bladder muscle that cannot pump fluid out efficiently
- Urinary retention (where too much urine remains trapped in the bladder after peeing)
- Underlying factors behind frequent urinary tract infections (UTIs) or urge incontinence
Our Commitment
Care you can trust
Every test is delivered to the same standard: senior consultants, a personalised plan, and the safety of an accredited private hospital behind you.
Consultant-Led Excellence
Receive evidence-based treatments delivered by senior NHS consultants in a professional, specialist setting.
Personalised Care Plans
Your consultant will design a bespoke treatment plan tailored to your specific health goals and lifestyle.
Hospital-Grade Safety
We operate within leading private hospitals, adhering to strict CQC safety and technology standards.
A Heritage of Trust
Our partners bring decades of NHS and private experience, successfully managing thousands of patient cases.
Trusted Resources
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Patient Guidance
Frequently Asked Questions
Common questions about this test and what to expect
3 questions
For the flow rate machine to get a truly reliable reading, you generally need to pass at least 150ml of urine. This is why arriving with a properly full bladder is so important.
Reviewed 31 May 2026
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The results are instantaneous. The flow meter prints out your flow graph immediately, and the bladder scanner displays the residual volume on screen in seconds. Your urologist or nurse can discuss the findings with you before you leave the clinic.
Reviewed 31 May 2026
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This depends on what your consultant wants to find out. Some specialists prefer to test you while you are on your regular tablets to see how well they are working, while others may ask you to stop them temporarily. Always check with your clinic or urology team beforehand.
Reviewed 31 May 2026
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