Diagnosis of OAB

A complete medical history, including a voiding diary; a physical examination; and one or more diagnostic procedures can help your health care provider diagnose any underlying condition and devise an appropriate treatment plan for overactive bladder.

Medical History & OAB Diagnosis

The medical history includes information about bowel habits, patterns of urination and leakage (when, how often, how severe), and whether there is pain, discomfort, or straining when voiding. A history of illnesses, pelvic surgeries, pregnancies, and list of medications (prescription and over-the-counter) also can supply information relevant to making a diagnosis. In the elderly, a mental status evaluation and assessment of social and environmental factors also may be performed.

Physical Examination & OAB Diagnosis

A physical examination includes a neurologic status evaluation and examination of the abdomen, rectum, genitals, and pelvis. The cough stress test, in which the patient coughs forcefully while the physician observes the urethra, allows observation of urine loss. Instantaneous leakage with coughing indicates a diagnosis of stress incontinence. Leakage that is delayed or persistent after the cough indicates urge incontinence.

The physical examination also helps the physician identify medical conditions that may be the cause of overactive bladder. For instance, poor reflexes or sensory responses may indicate a neurological disorder.

Urinalysis & OAB Diagnosis

Examination of the urine may identify medical conditions associated with overactive bladder, such as the following:

  • Bacteriuria-presence of bacteria in urine; indicates infection
  • Glycosuria-excess glucose in urine; may indicate diabetes
  • Hematuria-blood in urine; may indicate kidney disease
  • Proteinuria-excess protein in urine; may indicate kidney disease, cardiac disease, blood disease
  • Pyuria-presence of pus in urine; indicates infection

Specialized Testing & OAB Diagnosis

If overactive bladder persists after diagnosis and treatment, additional testing may be needed. Urologists perform urodynamic, endoscopic, and imaging tests to obtain a more extensive evaluation of the lower urinary tract to determine a new treatment plan.

Postvoid Residual Volume (PRV) & OAB Diagnosis

This procedure requires catheterization or pelvic ultrasound. The patient voids just before the PRV is measured. This initial void should be observed for hesitancy, straining, or interrupted flow. A PRV less than 50 mL indicates adequate bladder emptying. Repeated measurements of 100 to 200 mL or higher represent inadequate bladder emptying. The clinical setting and the patient's readiness to void may affect the test result; therefore, repeated measurements may be necessary.

Urodynamic Testing & OAB Diagnosis

Cystometry may be used to measure the anatomic and functional status of the bladder and urethra. The cystometer is an instrument that measures the pressure and capacity of the bladder; thus evaluating the function of the detrusor muscle. Simple cystometry detects abnormal detrusor compliance, but abdominal pressure is not included and the results must be evaluated with caution.

The multichannel, or subtracted, cystometrogram simultaneously measures intra-abdominal, total bladder, and true detrusor pressures. This allows involuntary detrusor contractions to be distinguished from increased intra-abdominal pressure. The voiding cystometrogram detects outlet obstruction in patients who are able to void.

Uroflowmetry identifies abnormal voiding patterns. Urethral pressure profilometry measures the resting and dynamic pressures in the urethra.

Endoscopic Tests & OAB Diagnosis

Cystoscopy may be performed when urodynamic testing fails to duplicate symptoms, when the patient experiences new symptoms (e.g., cystitis, pain), or when urinalysis reveals a disease process (e.g., henaturia, pyuria). Cystoscopy identifies the presence of bladder lesions (e.g., cysts) and foreign bodies (e.g., stones).

Imaging Tests & OAB Diagnosis

X-rays and ultrasound may be used to evaluate anatomic conditions associated with overactive bladder. Imaging of the lower urinary tract before, during, and after voiding is helpful in examining the anatomy of the urinary bladder and urethra.

Publication Review By: Daniel Khouri, M.D., Stanley J. Swierzewski, III, M.D.

Published: 10 Jun 1998

Last Modified: 02 Apr 2014