Diagnostic Test
Ultrasound
A safe, radiation-free scan using sound waves to look at your kidneys, bladder, and scrotum. It is a key first step for urologists to check for stones, lumps, or blockages.
Key Takeaways
- A safe, radiation-free scan using sound waves to look at your kidneys, bladder, and scrotum. It is a key first step for urologists to check for stones, lumps, or blockages.
- We offer specialist interpretation and related treatments. Book a consultation to discuss your options.
Overview
About Ultrasound
A urological ultrasound is a safe and painless way to see what is happening inside your body in real-time. Instead of using X-rays or radiation, it uses high-frequency sound waves sent through a handheld device called a probe.
In the UK, urology clinics typically use this to look at three main areas:
The Kidneys (Renal): Checking their size, shape, and health.
The Bladder: Seeing how much it can hold and how well it empties.
The Testicles (Scrotal): Checking for lumps or swelling.
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 very straightforward. You will be asked to lie on a couch, and a specialist (a sonographer or radiologist) will apply a clear, water-based gel to your skin. This gel helps the sound waves travel from the probe into your body.
The specialist will move the probe over your skin to get a clear view from different angles. You might be asked to roll onto your side or hold your breath for a few seconds. If you are having your bladder checked, you will often be scanned with a full bladder, asked to go and pee, and then scanned again to see how much urine is left.
The test is generally very comfortable. The gel might feel a bit cold when it first touches your skin, and you may feel some pressure from the probe—especially if your bladder is very full. For scrotal scans, the specialist will be very gentle, though there may be slight tenderness if the area is already sore or inflamed.
This is often the first "look" a doctor will take if you are experiencing symptoms like pain in your side (flank pain), blood in your pee, or if you have found a new lump in your scrotum. It is an excellent way to tell the difference between a harmless fluid-filled cyst and a more solid lump that might need further investigation.
At a glance
Preparation required
- Kidney or Bladder Scans: You usually need a full bladder. We recommend drinking about 500ml to 1 litre of water an hour before your appointment.
- Scrotal Scans: No special preparation or full bladder is needed for this.
- Clothing: Wear loose, comfortable clothes. You may need to move your clothing to allow the probe to reach your tummy or groin area.
- Medication: You can keep taking all your usual medicines as normal.
Risks or considerations
- Completely Safe: There is no radiation involved, so the test is safe to have multiple times if needed.
- Full Bladder is Key: If your bladder isn't full enough for a renal scan, the images might not be clear enough, and you may need to wait and drink more water.
- Limitations: Ultrasound waves cannot see through bone or gas, so sometimes a CT scan is needed to get a better look at certain parts of the "water pipes" (ureters).
- Body Type: In some cases, it can be harder to get clear images of deep organs if a patient has a high BMI.
What it can help diagnose
- Kidney and Bladder Stones: Spotting hard mineral deposits.
- Hydronephrosis: Swelling of the kidney caused by a blockage.
- Kidney Cysts and Tumours: Checking for unusual growths.
- Testicular Issues: Identifying testicular cancer, fluid-filled sacs (hydrocoeles), or cysts.
- Varicocoeles: Enlarged veins within the scrotum.
- Urinary Retention: Measuring how much urine stays in the bladder after you’ve been to the toilet.
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
A full bladder acts as a 'window' for the sound waves. When the bladder is empty, it collapses and hides behind the pelvic bones or is obscured by the bowel. When it's full of fluid, it pushes the bowel out of the way and provides a clear view of the bladder wall and the surrounding prostate or pelvic structures.
Reviewed 2 Mar 2026
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Yes, usually. Ultrasound is excellent at telling the difference between a simple cyst (which is filled with fluid and appears black on the screen) and a solid mass (which appears grey). Fluid-filled cysts are almost always benign, whereas solid lumps require further investigation, such as an MRI or a biopsy.
Reviewed 2 Mar 2026
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This is a two-part test often done during a bladder scan. First, we scan you with a full bladder to see its capacity. Then, you are sent to the bathroom to pee, and we scan you again immediately after. This tells us exactly how many millilitres of urine are 'left over'—helping us diagnose issues like an enlarged prostate or a weak bladder muscle.
Reviewed 2 Mar 2026
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