Diagnostic Test
Flow Rate Test (Uroflowmetry)
A simple, non-invasive test to measure the strength and pattern of your urinary stream. Used by urologists to help diagnose bladder or prostate issues.
Key Takeaways
- A simple, non-invasive test to measure the strength and pattern of your urinary stream. Used by urologists to help diagnose bladder or prostate issues.
- We offer specialist interpretation and related treatments. Book a consultation to discuss your options.
Overview
About Flow Rate Test (Uroflowmetry)
A flow rate test (uroflowmetry) is a quick and painless way for your specialist to see how well your bladder and the tube which empties your bladder (the urethra) are working. Instead of just describing your symptoms, this test provides a graphical representation of your urine flow, measuring how much urine comes out, how fast it flows, the pattern of the flow, and how long it takes to empty your bladder.
Ordinarily a bladder scan will be performed after a flow rate test to assess whether you are emptying the bladder effectively.
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 test is designed to be as natural as possible. You will be shown to a private room or a specially equipped toilet and asked to pee into a device called a flow meter. This looks like a funnel or a commode and contains sensors that record your stream in real-time.
It is important to pee as naturally as you would at home. Please do not try to "push" or "force" the urine out, nor squeeze the penis in males, as this can make the results look different from your usual habit.
The test itself is completely painless and non-invasive. The only potential discomfort is the feeling of a full bladder while you wait for your turn. Clinics aim to provide a stress-free environment, but if you feel nervous or have a "shy bladder," please let the staff know so they can help you feel more comfortable.
This test can help establish the severity, and suggest potential causes for urinary symptoms. Urologists can use these results to see if there is a physical blockage (like an enlarged prostate) or if your bladder muscle isn't squeezing as hard as it should. It is a vital step before starting any new medications or considering surgery for urinary issues.
At a glance
Preparation required
- Arrive with a comfortably full bladder: You should feel the urge to go, but you shouldn't be in pain.
- Hydrate beforehand: We usually recommend drinking about 500ml to 750ml of water one hour before your appointment.
- Don’t over-fill: If your bladder is too full, the muscle can temporarily stretch and weaken, which may skew the results.
- Volume matters: For the test to be valid, you usually need to pass at least 150ml of urine.
Risks or considerations
- No physical risks: Since nothing is inserted into the body, there are no physical side effects.
- Inaccurate results: If you don't drink enough water and pass less than 150ml, the test may need to be repeated.
- Shy bladder: Some people find it difficult to pee on demand in a clinical setting. This is very common, and your consultant is used to it.
What it can help diagnose
- Benign Prostatic Hyperplasia (BPH): An enlarged prostate that narrows the water pipe.
- Urethral Strictures: Scar tissue that narrows the pipe.
- Overactive or Underactive Bladder: Issues with how the bladder muscle functions.
- Prostate Cancer: If it is causing an obstruction to the flow.
- Bladder Neck Contracture: A narrowing at the exit of the bladder.
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.
Patient Guidance
Frequently Asked Questions
Common questions about this test and what to expect
3 questions
This is very common and is often called 'shy bladder.' If you are unable to urinate, don't worry—the clinical staff will simply give you more water to drink and allow you to wait in a quiet area until you feel ready. The test is performed in a private bathroom, so there is no one watching or hovering while you void.
Reviewed 2 Mar 2026
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For the results to be clinically valid, you generally need to pass at least 150ml of urine. If your bladder is only partially full, the flow rate may appear falsely low. Conversely, if you are 'bursting' and in pain, the bladder muscle can become overstretched and perform poorly. Aim for the feeling of a 'standard' morning bathroom trip.
Reviewed 2 Mar 2026
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The flow test tells us the speed of the urine, but it doesn't tell us if your bladder is empty. A quick, non-invasive ultrasound (Post-Void Residual scan) is done right after you pee to see if any urine is 'stagnating' in the bladder. This helps us distinguish between a blockage in the pipe and a bladder that has lost its strength.
Reviewed 2 Mar 2026
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