Urodynamic Testing: Overview and Instructions

What is Urodynamic Testing?

Urodynamic testing (also called urodynamics or UDS) is a series of diagnostic tests that evaluate bladder function and identify the cause of urinary problems. These tests measure:

How much your bladder can hold
How much pressure builds up as it fills
How well your bladder empties
Whether involuntary contractions occur
How well your sphincter muscles work
Urethral function and resistance

The information helps your doctor diagnose conditions and plan the most effective treatment.

Why Your Doctor Ordered This Test

Urodynamics can help diagnose and evaluate:

Incontinence Issues

Stress incontinence (leakage with coughing, sneezing)
Urge incontinence (sudden strong need to urinate)
Mixed incontinence
Overflow incontinence

Voiding Problems

Difficulty starting urination
Weak stream
Incomplete bladder emptying
Urinary retention

Bladder Dysfunction

Overactive bladder
Underactive bladder
Neurogenic bladder
Interstitial cystitis

Other Conditions

Frequent urinary tract infections
Pelvic organ prolapse
Before incontinence surgery
After failed previous treatments

Types of Urodynamic Tests

1. Uroflowmetry

What it measures: How fast urine flows when you urinate

How it's done: You urinate privately into a special toilet/funnel that measures flow rate and volume

Duration: As long as it takes you to urinate

Discomfort level: None - just normal urination

2. Post-Void Residual (PVR)

What it measures: How much urine remains in bladder after you void

How it's done: Ultrasound scan of bladder immediately after urination (OR catheter measurement)

Duration: 1-2 minutes

Discomfort level: None with ultrasound; mild with catheter

Normal PVR: Less than 50-100 mL

3. Cystometry (Bladder Pressure Study)

What it measures: Bladder pressure and capacity during filling

How it's done:

Small catheter placed in bladder through urethra
Another small catheter may be placed in rectum or vagina to measure abdominal pressure
Bladder slowly filled with sterile water
You report sensations: first urge, strong urge, maximum capacity
Pressures measured throughout filling

Duration: 15-30 minutes

Discomfort level: Mild - feels like need to urinate

4. Pressure Flow Study (Voiding Study)

What it measures: Bladder pressure and urine flow during voiding

How it's done: While catheters are in place, you urinate and we measure:

Pressure generated by bladder muscle
Flow rate of urine
Coordination of bladder and sphincter

Duration: 5-10 minutes

Discomfort level: Mild - urinating with catheter in place feels unusual

5. Electromyography (EMG)

What it measures: Electrical activity of pelvic floor muscles and sphincters

How it's done: Small adhesive patches or sensors placed near urethra and anus

Duration: Measured throughout other tests

Discomfort level: None - just sensors on skin

6. Leak Point Pressure Test

What it measures: Pressure at which urine leaks from bladder

How it's done: With bladder partially filled, you cough or strain and we measure when leakage occurs

Duration: 5 minutes

Purpose: Helps diagnose stress incontinence severity

How to Prepare for Your Urodynamic Test

Before Your Appointment

Drink fluids 1-2 hours before so you arrive with comfortably full bladder
- NOT painfully full - just normal urge to urinate
- We need you able to urinate for uroflowmetry
Take all regular medications unless specifically told otherwise
Wear comfortable, loose clothing - you'll need to undress from waist down
Bring medication list including over-the-counter and supplements
No special bowel preparation required
No fasting required - eat and drink normally (except arrival with full bladder)

Inform Us If You Have:

Active urinary tract infection or symptoms (burning, fever, frequency with pain)
Allergy to latex or local anesthetics (lidocaine)
Difficulty with catheter placement in the past
Current menstrual period (may affect study)
Pregnancy or possible pregnancy
Cardiac pacemaker or defibrillator

What to Expect During Testing

Arrival and Setup (5-10 minutes)

Check in and change into gown
Tech explains procedure
Position on specialized exam chair/table
EMG sensors applied if needed

Testing Sequence (30-60 minutes total)

Phase 1: Baseline Uroflowmetry (3-5 minutes)

You urinate privately into special toilet
Measures your natural flow rate and pattern
No discomfort

Phase 2: Post-Void Residual (1-2 minutes)

Ultrasound scan or brief catheter measures remaining urine
Minimal to no discomfort

Phase 3: Catheter Placement (2-5 minutes)

Small catheter inserted through urethra into bladder (with lubricating gel)
Second catheter may be placed in rectum or vagina
Brief discomfort during insertion, then sensation of fullness
Local anesthetic gel used to minimize discomfort

Phase 4: Filling Cystometry (15-25 minutes)

Bladder slowly filled with sterile warm water or saline
You'll report sensations as bladder fills:
- First sensation of filling
- First desire to void
- Strong desire to void
- Maximum capacity
Pressures recorded throughout
You may be asked to cough or strain during filling

Phase 5: Voiding Pressure-Flow Study (5-10 minutes)

With catheters still in place, you urinate
Measures bladder pressure and flow rate simultaneously
Feels unusual to void with catheter in place but is safe
You'll be given privacy during this phase

Phase 6: Catheter Removal & Cleanup (2-3 minutes)

Catheters removed quickly
Brief moment of relief
Clean up and get dressed

What You'll Be Asked to Do

Report sensations accurately: Tell us when you first feel fullness, urge, etc.
Cough when requested: Helps us measure leak point pressures
Strain or bear down: As if having bowel movement (when asked)
Try to inhibit urge: Hold urine when bladder is full
Urinate on command: Even though catheters are in place
Communicate: Speak up if you're uncomfortable

After the Test

Immediate Recovery

No recovery time needed - resume all activities immediately
Drive home: You can drive yourself (no anesthesia used)
Work: Return to work same day if desired
Exercise: No restrictions

Normal Post-Test Symptoms

✅ Expected (Not Concerning)

Mild burning with first 2-3 urinations
Frequency: Need to urinate more often for a few hours
Small amount of blood in urine (usually just first void)
Awareness of urethra: Mild sensitivity

These symptoms typically resolve within 24 hours.

Post-Test Care

Hydration: Drink extra fluids for 24 hours (helps flush urinary system)
Pain relief: Tylenol or ibuprofen if needed for mild discomfort
Avoid: No restrictions - resume all normal activities

🚨 Call 678-344-8900 If You Experience:

🌡️ Fever over 100.4°F or chills
🚫 Unable to urinate within 4-6 hours after test
😖 Severe pain that doesn't improve
🩸 Heavy bleeding or blood clots
🤮 Persistent nausea or vomiting

These complications are rare but call immediately if they occur.

Understanding Your Results

Key Measurements

Measurement	What It Means	Normal Range
Maximum flow rate (Qmax)	Peak urine flow	>15 mL/sec (men) >20 mL/sec (women)
Post-void residual	Urine left after voiding	<50-100 mL
Bladder capacity	Maximum comfortable volume	300-500 mL
First sensation	When you first feel filling	100-200 mL
Detrusor pressure	Bladder muscle pressure	<15 cmH2O at rest
Compliance	Bladder wall stretchiness	>20 mL/cmH2O

What Results Can Show

Bladder Storage Problems

Overactive bladder (detrusor overactivity)
Low capacity
Poor compliance (stiff bladder)
Stress incontinence

Emptying Problems

Bladder outlet obstruction
Weak bladder muscle (detrusor underactivity)
Poor coordination (dyssynergia)
Incomplete emptying

Your doctor will explain your specific results and what they mean for your treatment plan.

Frequently Asked Questions

Will it hurt?

Most patients experience only mild discomfort. The catheter insertion feels like brief pressure. During filling, you'll feel progressively stronger urge to urinate. We use anesthetic gel to minimize discomfort.

How long does it take?

Total time is typically 30-60 minutes including setup and cleanup. The actual testing is about 20-40 minutes. Complex studies may take longer.

Do I need someone to drive me?

No - no sedation is used, so you can drive yourself. However, arrange a driver if you're very anxious or uncomfortable.

Can I eat beforehand?

Yes - eat and drink normally. We actually need you to arrive with a comfortably full bladder, so drink fluids 1-2 hours before.

What if I can't urinate with catheter in?

This is common - the catheter and situation are unusual. Take your time, relax, and the tech will coach you. Most patients are able to complete the study.

Is there risk of infection?

Risk is very low (less than 1%). We use sterile technique. Drink extra fluids after and call if you develop fever or worsening symptoms.

When will I get results?

Your doctor will review the study and discuss results at your follow-up appointment, typically within 1-2 weeks.

Do I need antibiotics?

Usually not needed for urodynamics. We'll prescribe only if you have specific risk factors.

Special Situations

Video Urodynamics

In some cases, we may perform video urodynamics, which adds real-time X-ray imaging (fluoroscopy) during the study. This provides even more detailed information about bladder and urethral function.

Additional considerations:

Contrast dye used instead of water
Slightly longer study time
Visual recording of bladder/urethra during filling and voiding
Helpful for complex cases

Ambulatory Urodynamics

For some patients with complex symptoms, we may use ambulatory urodynamics, where catheters remain in place for several hours while you go about normal activities. Your doctor will explain if this specialized test is needed.

Why This Test Matters

Urodynamic testing provides objective data that guides treatment decisions. It can:

✅ Confirm Diagnosis

Distinguish between types of incontinence
Identify obstruction vs weak bladder
Quantify severity

✅ Guide Treatment

Choose right medication
Determine if surgery would help
Predict surgery success rates

✅ Monitor Progress

Track response to treatment
Adjust therapy as needed
Compare before/after intervention

✅ Prevent Complications

Identify upper tract risk
Detect high pressures
Protect kidney function

Questions?

Call Advanced Urology: 678-344-8900

Monday through Friday, 8:00 AM - 5:00 PM

Our team is available to answer questions about your urodynamic testing and help you prepare for your appointment.