Uroflowmetry: what kind of test is it and what does it show

Uroflowmetry is a non-invasive method for studying urodynamics: during normal urination, the device records the volumetric flow rate of urine and other physiological parameters. The test provides insight into detrusor contractile activity and urethral patency. The measuring device is called a uroflowmeter, and the resulting graph is called a uroflowgram.

What uroflowmetry is and what it measures

Uroflowmetry measures the volume of urine passed, the rate at which it is passed, and the duration of the act. The method is non-invasive, simple to perform, and informative. The results are used to assess the evacuation function of the bladder, the degree of opening of the bladder neck, and the resistance of the vesicourethral segment. The significance of the test for a urologist is compared to the significance of an ECG for a cardiologist.

Why uroflowmetry is ordered

The test is used to assess the function of the urinary system, most often for complaints of urination that is too slow. The method is included in the list of tests recommended by the European Association of Urology for detecting prostatic hyperplasia and is used in urogynecological diseases. Uroflowmetry makes it possible to objectify the nature and degree of urination impairment, to monitor the course of treatment and the effectiveness of reconstructive and restorative surgery, including urethroplasty for urethral strictures. The method is also particularly suitable for identifying voiding dysfunction in children.

How the test is performed

The patient urinates into a urological device or a toilet equipped with a measuring device; urination should begin after the machine is started. Preparation is determined by the doctor: usually the test is performed with a full bladder — the patient should not urinate for at least 2 hours beforehand, and drinking more fluids in advance may also be recommended. The result is most reliable when the urine volume is at least 150 milliliters. The doctor may ask the patient to temporarily stop taking medications that affect the result. Paper must not be placed in the device. The test is painless and carries no risks.

What the urine flow curve shows

The uroflowgram is a graphical representation of the volumetric flow rate during spontaneous urination. It is used to assess the type of urination (normal, intermittent, interrupted, obstructive, rapid, depressive) and to suspect infravesical obstruction. A decreased flow is observed with obstruction of the bladder outlet or weakness of the bladder muscle; increased flow and incontinence occur with weakness or dysfunction of the circular muscles around the urethra. Normal values depend on age and sex: in men, flow rate decreases with age, while in women it changes less.

Residual urine analysis: what it is and when it is determined

The volume of urine remaining in the bladder after urination can be measured using ultrasound; the doctor compares it with the patient's complaints and the uroflowmetry results. Residual urine is one of the signs described in evacuation voiding disorders.

How to understand the result and what to discuss with a urologist

Results are compared with complaints and examination findings: a value that requires treatment in one person may not require intervention in another. The type of curve, the residual urine volume, and how the numbers relate to symptoms should be discussed with a urologist. Medical attention is sought for difficult or frequent urination, a weak stream, or a feeling of incomplete emptying. Evaluation for suspected enlarged prostate may include a urine test, a PSA test, bladder ultrasound, and cystoscopy.

• Difficulty initiating urination, need to strain
• Weak stream, intermittent urination, prolonged emptying
• Feeling of incomplete bladder emptying, dribbling after urination
• Frequent or urgent urges, nighttime urination

Difficult urination alone is not a reason to call emergency services; 103 or 112 — if the person cannot urinate at all, blood has appeared in the urine (pink, red, or brown), or urination is accompanied by pain.

This material is for reference purposes and does not replace consultation with a doctor.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer