Why Are Bladder Investigations Necessary?

If you’re experiencing urinary symptoms—whether it’s frequent urination, incontinence, pain when urinating, or difficulty emptying your bladder—you may need diagnostic tests to find out what’s going on. These investigations help your doctor distinguish between different conditions that can cause similar symptoms.

Urinary incontinence, for example, isn’t a disease in itself. It’s a symptom that can arise from many different causes: childbirth trauma, pelvic surgery, spinal cord injuries, neurological conditions like multiple sclerosis, infections, or simply age-related changes. Temporary incontinence might result from a urinary tract infection, excessive alcohol consumption, or dehydration. Working out which of these applies to you requires proper investigation.

I won’t pretend these tests are anyone’s idea of a good time. Some are straightforward (like peeing into a cup), while others are more involved (like having a thin camera inserted into your bladder). But understanding what to expect can make the process less daunting.

Getting Started: The Initial Consultation

Before any tests, your GP or specialist will take a detailed history. They’ll ask about your symptoms, when they started, what makes them better or worse, your fluid intake, medications, and relevant medical history. Be honest about your symptoms—doctors have heard it all before, and holding back information only makes diagnosis harder.

Many people feel embarrassed discussing bladder problems. A 2020 survey found that patients often wait years before seeking help for incontinence 1. This delay is unfortunate because most bladder conditions respond well to treatment when caught early.

Your doctor may ask you to keep a bladder diary for a few days before your appointment. This involves recording when you urinate, how much, any leakage episodes, and your fluid intake. It sounds tedious, but this information is genuinely useful for diagnosis.

Basic Investigations

Urinalysis (Dipstick Test)

The most basic test. You provide a urine sample, and a test strip is dipped in to check for signs of infection (white blood cells, nitrites), blood, protein, glucose, and other abnormalities. Results are available within minutes.

If infection is suspected, the sample may be sent for culture to identify the specific bacteria involved and which antibiotics will work against them. Culture results take a few days.

Physical Examination

For women, this may include a pelvic examination to check for prolapse or vaginal atrophy. Your doctor will assess pelvic floor muscle strength—they’ll ask you to squeeze as if stopping the flow of urine.

For men, a digital rectal examination checks the prostate gland for enlargement or abnormalities. This is particularly relevant if symptoms suggest benign prostatic hyperplasia (BPH) or prostate cancer.

A “cough test” may be performed: with a reasonably full bladder, you’ll be asked to cough while the examiner watches for involuntary urine leakage. This helps identify stress incontinence.

Post-Void Residual Measurement

After urinating, some urine may remain in your bladder. A significant residual volume (generally over 100ml) suggests incomplete emptying, which can occur with urinary retention, bladder muscle weakness, or obstruction.

This is usually measured using a portable ultrasound scanner—a quick, painless scan over your lower abdomen immediately after you’ve emptied your bladder. Alternatively, a thin catheter can be passed to drain and measure any remaining urine, though this is less commonly done now that portable ultrasounds are widely available.

Urodynamic Studies

Urodynamics is a blanket term for tests that assess how your bladder and urethra store and release urine. These are typically performed in a hospital outpatient setting and take 30-60 minutes. The NHS recommends urodynamic testing before surgery for stress incontinence to confirm the diagnosis and rule out other problems 2.

Uroflowmetry

The simplest urodynamic test. You urinate into a special toilet that measures flow rate and volume. The machine produces a graph showing your flow pattern. A normal flow is smooth and dome-shaped, with a peak rate of at least 15ml/second for women and 12ml/second for men.

An abnormal pattern—such as a prolonged, weak stream—might suggest obstruction (like an enlarged prostate) or weak bladder muscles. This test is non-invasive and painless, though some people find it difficult to urinate “on command” in a clinical setting.

Cystometry (Filling Cystometry)

This measures bladder pressure and capacity during filling. A thin catheter is inserted through your urethra into your bladder, and sometimes a second catheter is placed in the rectum or vagina to measure abdominal pressure. The bladder is then slowly filled with sterile water while pressures are recorded.

During filling, you’ll be asked to report when you first feel the urge to urinate, when the urge becomes strong, and when you can’t hold any more. The test also detects involuntary bladder contractions (detrusor overactivity), which cause urge incontinence and overactive bladder.

I’ll be frank: having a catheter inserted isn’t comfortable. It’s a brief sensation of pressure and mild stinging, typically lasting only a few seconds. Most people tolerate it well, though you may feel vulnerable.

Pressure-Flow Study

Often performed immediately after cystometry. While the catheters are still in place, you’re asked to urinate. The test measures the relationship between bladder pressure and urine flow. High pressure with low flow suggests obstruction; low pressure with low flow suggests a weak bladder muscle (detrusor underactivity).

Videourodynamics

In some centres, urodynamic testing is combined with X-ray imaging (fluoroscopy) to visualise the bladder and urethra during filling and voiding. This provides anatomical information alongside the pressure measurements and is particularly useful for complex cases or before surgical planning.

Cystoscopy

Cystoscopy involves inserting a thin telescope (cystoscope) through the urethra to look directly inside the bladder. It’s the gold standard for detecting bladder abnormalities that can’t be seen on scans.

Flexible Cystoscopy

Usually performed as an outpatient procedure using a thin, flexible scope. Local anaesthetic gel is applied to the urethra beforehand. The procedure takes 5-10 minutes.

You’ll feel pressure and an urge to urinate during the examination, but it shouldn’t be painful. Afterwards, you may experience some stinging when you urinate and see a small amount of blood in your urine for a day or two—this is normal.

Flexible cystoscopy is commonly used to investigate blood in the urine (haematuria), recurrent infections, suspected bladder cancer, and chronic bladder pain. It can detect tumours, stones, areas of inflammation, and structural abnormalities.

Rigid Cystoscopy

Performed under general or spinal anaesthesia, usually as a day-case procedure. The rigid scope provides better views and allows therapeutic procedures—taking biopsies, removing small tumours, treating bladder stones, or performing bladder instillations for conditions like interstitial cystitis.

Recovery is slightly longer than flexible cystoscopy. Expect some discomfort and blood in your urine for a few days. Drink plenty of fluids to flush through the bladder.

Imaging Studies

Ultrasound

Non-invasive, painless, and widely available. Ultrasound can assess kidney size and structure, detect stones or hydronephrosis (swelling of the kidney due to urine backup), and measure post-void residual urine in the bladder.

For bladder imaging, you’ll need a full bladder—typically you’re asked to drink water and not urinate for an hour before the scan. The sonographer applies gel to your abdomen and moves a handheld probe to capture images.

Ultrasound has limitations: it doesn’t visualise the bladder lining in detail and may miss small tumours. It’s often used as an initial screening tool rather than a definitive investigation.

CT Scan (CT Urogram)

CT urography provides detailed cross-sectional images of the kidneys, ureters, and bladder. It’s particularly good at detecting stones, tumours, and anatomical abnormalities. The scan uses X-rays and usually involves an injection of contrast dye through a vein in your arm.

The contrast dye may cause a warm flushing sensation and a metallic taste in your mouth—this passes quickly. Let the radiographer know if you have any allergies or kidney problems, as the contrast can occasionally cause reactions or affect kidney function.

A CT urogram is commonly performed for haematuria (blood in urine) investigation, especially in patients over 40 where the risk of urinary tract cancers is higher 3.

MRI

MRI provides excellent soft tissue detail without radiation exposure. It’s particularly useful for staging bladder and prostate cancers, assessing pelvic organ prolapse, and investigating complex pelvic pathology.

MRI scans are noisy (you’ll be given earplugs or headphones) and take longer than CT—typically 30-45 minutes. You need to lie still in a tunnel-shaped scanner. Let staff know if you’re claustrophobic; open MRI scanners and sedation are available in some centres.

Intravenous Urogram (IVU)

Largely replaced by CT urography, though still used in some settings. Contrast dye is injected, and a series of X-rays are taken as the dye passes through the kidneys and down the ureters. IVU is good at showing the shape of the urinary tract and detecting obstructions.

Specialist Tests

Pad Test

For objectively measuring urine leakage. You wear a pre-weighed pad for a set period (usually one hour, during which you drink a specific amount and perform standardised activities, or 24 hours for a home-based test). The pad is then weighed again. Weight gain corresponds to leaked urine volume.

This is useful for assessing incontinence severity and monitoring response to treatment.

Electromyography (EMG)

Measures electrical activity in the pelvic floor muscles and sphincters. Small sensors (either surface patches or needle electrodes) detect muscle activity during filling and voiding. EMG can identify coordination problems between the bladder and pelvic floor, particularly in neurogenic bladder disorders.

Video Recording of Symptoms

For intermittent symptoms that are difficult to reproduce in clinic, your doctor might ask you to record episodes on your phone—for example, visible leakage during exercise, or the appearance of your urinary stream. This sounds unusual but can provide valuable diagnostic information.

After Your Investigations

Once results are available, your specialist will explain the findings and discuss treatment options. Many bladder conditions respond to conservative measures—pelvic floor exercises, bladder training, lifestyle modifications, or medication. Surgery is reserved for cases where simpler approaches haven’t worked.

Don’t be afraid to ask questions. If you don’t understand something, say so. If you want to know why a particular test was or wasn’t recommended, ask. You’re entitled to understand your own health.

Seeking Help

Many people delay seeking help for bladder problems due to embarrassment. A large European survey found the average patient waits over four years before consulting a doctor about incontinence 1. This delay is unnecessary and often means people suffer in silence when effective treatments exist.

If bladder symptoms are affecting your quality of life, speak to your GP. They can perform initial assessments and refer you to a specialist if needed—typically a urologist or urogynaecologist. In some areas, continence clinics run by specialist nurses offer self-referral, meaning you can book an appointment directly without seeing your GP first. These nurses are specifically trained in bladder and bowel problems and can advise on treatment pathways.

Don’t let bladder problems control your life. The investigations might not be pleasant, but they’re the first step toward getting proper treatment and regaining control.

References

Lukacz ES, et al. “A healthy bladder: a consensus statement.” Int J Clin Pract. 2011;65(10):1026-1036.
NHS. “Urinary incontinence - Diagnosis.” nhs.uk
Linder BJ, et al. “Guideline of Guidelines: Asymptomatic Microscopic Haematuria.” BJU Int. 2020;126(2):189-195.