Kidneys, Ureters & Bladder Ultrasound Scan

What is a Kidneys, Ureters & Bladder Ultrasound Scan?

A Kidneys, Ureters & Bladder (KUB) Ultrasound Scan is a non-invasive imaging test that uses high-frequency sound waves to produce real-time images of the urinary tract. It does not use ionising radiation and is considered very safe.

This scan assesses the kidneys, ureters (the tubes connecting kidneys to the bladder) and the bladder itself. It allows clinicians to evaluate organ size, structure, fluid flow, bladder volume and post-void residual urine.

KUB ultrasound is commonly used as a first-line investigation for urinary symptoms, kidney problems and abnormal blood or urine test results.

Why do I need a KUB Ultrasound Scan?

A KUB ultrasound scan is recommended when symptoms or test results suggest a possible issue affecting the kidneys or urinary system. It helps identify the cause of urinary symptoms quickly and accurately.

You may need a KUB ultrasound scan if you experience:

• Flank or lower back pain
• Blood in the urine (haematuria)
• Recurrent urinary tract infections
• Pain or difficulty passing urine
• Frequent or urgent urination
• Suspected kidney or bladder stones
• Reduced urine output
• Abnormal kidney function blood tests
• Urinary retention or incomplete bladder emptying
• Monitoring of known kidney or bladder conditions

Early imaging supports timely diagnosis and helps prevent complications such as kidney damage.

Benefits of a KUB Ultrasound Scan

• Safe, radiation-free imaging
  Suitable for repeated use and long-term monitoring.
• Real-time urinary tract assessment
  Visualises kidney structure and bladder filling/emptying.
• Detects stones and obstruction
  Identifies kidney stones, bladder stones and urinary blockage.
• Assesses kidney size and health
  Helps evaluate chronic or acute kidney conditions.
• Evaluates bladder function
  Measures residual urine after voiding.
• Fast and accessible
  Often performed and explained on the same day.
• Non-invasive and painless
  No needles or injections required.
• Cost-effective first-line test
  Often avoids unnecessary CT or invasive investigations.

Step-by-Step – How We Offer KUB Ultrasound Scans

Clinic-Based KUB Ultrasound Scan (UK-wide)

• Choose your nearest UK clinic
• Attend your scheduled appointment
• The scan typically takes 15–30 minutes
• Performed by an experienced clinician
• Findings are explained during or shortly after the scan

Important:
KUB ultrasound scans are performed in clinic only. Home visits are not available. Services are available across the UK.

Your KUB Ultrasound Results Explained

KUB ultrasound results are interpreted based on organ size, structure and urinary flow, rather than numerical values.

Normal Results

What this means:

• Normal kidney size and appearance
• No stones, obstruction or abnormal fluid
• Normal bladder filling and emptying

What it suggests:
Urinary symptoms may be functional or temporary.

Mild to Moderate Abnormal Findings

What this may show:

• Small kidney or bladder stones
• Mild kidney swelling (hydronephrosis)
• Incomplete bladder emptying
• Mild structural changes

What it suggests:
Often managed with medication, hydration, monitoring or lifestyle advice.

Significant or Severe Abnormal Findings

What this may show:

• Large stones
• Significant urinary obstruction
• Marked kidney swelling
• Significant post-void urine retention

What it suggests:
May require urgent referral, further imaging or specialist treatment.