Urinary frequency is the need to urinate many times during the day, at night (nocturia), or both but in normal or less-than-normal volumes. Frequency may be accompanied by a sensation of an urgent need to void (urinary urgency). Urinary frequency is distinguished from polyuria, which is urine output of >3 L/day.
Pathophysiology
Urinary frequency usually results from disorders of the lower genitourinary tract. Inflammation of the bladder, urethra, or both causes a sensation of the need to urinate. However, this sensation is not relieved by emptying the bladder, so once the bladder is emptied, patients continue trying to void but pass only small volumes of urine.
Etiology
There are many causes of urinary frequency (see table Some Causes of Urinary Frequency), but the most common include
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Urinary tract infections (UTIs)
Some Causes of Urinary Frequency
Cause |
Suggestive Findings |
Diagnostic Approach |
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Progressive onset of urinary hesitancy, incontinence, poor urine stream, a sensation of incomplete voiding |
Rectal examination Ultrasonography Cystometry |
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Urinary incontinence Sensation of vaginal fullness Pain or urinary leakage during sexual intercourse |
Pelvic examination Voiding cystourethrography |
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Drugs and substances |
Urinary frequency in an otherwise healthy patient |
Empiric elimination of offending substance (to confirm that frequency resolves) |
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Pregnancy |
3rd trimester of pregnancy |
Clinical evaluation |
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Urgency, dysuria, nocturia, purulent urethral discharge with fever, chills, low back pain, myalgia, arthralgia, and perineal fullness Prostate tender to palpation |
Rectal examination Culture of secretions after prostatic massage |
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Radiation cystitis |
History of radiation therapy of the lower abdomen, prostate, or perineum for treatment of cancer |
Clinical evaluation Cystoscopy and biopsy |
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Asymmetric arthritis of knees, ankles, and metatarsophalangeal joints Unilateral or bilateral conjunctivitis Small, painless ulcers on the mouth, tongue, glans penis, palms, and soles 1–2 weeks after sexual contact |
STD testing |
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Lower-extremity weakness, decreased anal sphincter tone, absent anal wink reflex Loss of sensation at a segmental level Injury usually clinically obvious |
MRI of the spine |
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Hesitancy, tenesmus, reduced caliber and force of the urine stream |
Urethrography |
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Unintentional passage of urine, particularly when bending, coughing, or sneezing |
Cystometry |
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Colicky flank or groin pain |
Urinalysis for hematuria Ultrasonography or CT of the kidneys, ureters, and bladder |
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Dysuria and foul-smelling urine, sometimes fever, confusion, and flank pain, particularly in women and girls Dysuria and frequency in young sexually active men (which suggests an STD) |
Urinalysis and culture STD testing |
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Bladder detrusor overactivity |
Nocturia, urge incontinence, weak urinary stream, and sometimes urinary retention |
Cystometry |
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STD = sexually transmitted disease. |
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Evaluation
History
History of present illness should first ask about the amounts of fluid consumed and voided to distinguish between urinary frequency and polyuria. If urinary frequency is present, patients are asked about acuity of onset, presence or absence of irritative symptoms (eg, irritation, urgency, dysuria), obstructive symptoms (eg, hesitancy, poor flow, sensation of incomplete voiding, nocturia), and recent sexual contacts.
Review of systems should cover symptoms suggestive of a cause, including fever, flank or groin pain, and hematuria (infection); missed menses, breast swelling, and morning sickness (pregnancy); and arthritis and conjunctivitis (reactive arthritis).
Past medical history should ask about known causes, including prostate disease and previous pelvic radiation therapy or surgeries. Drugs and diet are reviewed for the use of agents that increase urine output (eg, diuretics, alcohol, caffeinated beverages).
Physical examination
Examination focuses on the genitourinary system.
Any urethral discharge or any lesions consistent with sexually transmitted diseases are noted. Rectal examination in men should note the size and consistency of the prostate and rectal tone; pelvic examination in women should note the presence of any cystocele. Patients should be instructed to cough while the urethra is observed for signs of urinary leakage.
The costovertebral angle should be palpated for tenderness, and the abdominal examination should note the presence of any masses or suprapubic tenderness.
Neurologic examination should test for lower-extremity weakness and loss of sensation.
Red flags
Interpretation of findings
Dysuria suggests frequency is due to urinary tract infection (UTI) or calculi. Prior pelvic surgery suggests incontinence. Weak urine stream, nocturia, or both suggests benign prostatic hyperplasia (BPH). Urinary frequency in an otherwise healthy young patient may be due to excessive intake of alcohol or caffeinated beverages. Gross hematuria suggests UTI and calculi in younger patients and genitourinary cancer in older patients.
Testing
All patients require urinalysis and culture, which are easily done and can detect infection and hematuria.
Cytoscopy, cystometry, and urethrography can be done to diagnose cystitis, bladder outlet obstruction, and cystocele. Prostate-specific antigen level determination, ultrasonography, and prostate biopsy may be required, especially in older men, to differentiate BPH from prostate cancer.
Treatment
Geriatrics Essentials
Urinary frequency in elderly men is often caused by bladder neck obstruction secondary to prostate enlargement or cancer. These patients usually require postvoid residual urine volume determination. Urinary tract infection (UTI) or use of diuretics may be a cause in both sexes.
