Urinary Frequency: A Merck Manual of Patient Symptoms podcast

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 GU 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 8: Symptoms of Genitourinary Disorders: Some Causes of Urinary Frequency), but the most common include

• UTIs
• Urinary incontinence
• Benign prostatic hyperplasia (BPH)
• Urinary tract calculi

Table 8
PrintOpen table in new window
Some Causes of Urinary Frequency Cause Suggestive Findings Diagnostic Approach Benign prostatic hyperplasia or prostate cancer Progressive onset of urinary hesitancy, incontinence, poor urine stream, a sensation of incomplete voiding Rectal examination Ultrasonography Cystometry Cystocele Urinary incontinence Sensation of vaginal fullness Pain or urinary leakage during sexual intercourse Pelvic examination Voiding cystourethrography Drugs and substances Caffeine Alcohol Diuretics Urinary frequency in an otherwise healthy patient Empiric elimination of offending substance (to confirm that frequency resolves) Pregnancy 3rd trimester of pregnancy Clinical evaluation Prostatitis 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 Radiation cystitis History of radiation therapy of the lower abdomen, prostate, or perineum for treatment of cancer Clinical evaluation Cystoscopy and biopsy Reactive arthritis 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 wk after sexual contact STD testing Spinal cord injury or lesion Lower-extremity weakness, decreased anal sphincter tone, absent anal wink reflex Injury usually clinically obvious MRI of the spine Urethral stricture Hesitancy, tenesmus, reduced caliber and force of the urine stream Urethrography Urinary incontinence Unintentional passage of urine, particularly when bending, coughing, or sneezing Cystometry Urinary tract calculi Colicky flank or groin pain Urinalysis for hematuria Ultrasonography or CT of the kidneys, ureters, and bladder UTIs 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 STD = sexually transmitted disease. Some Causes of Urinary Frequency Cause Suggestive Findings Diagnostic Approach Benign prostatic hyperplasia or prostate cancer Progressive onset of urinary hesitancy, incontinence, poor urine stream, a sensation of incomplete voiding Rectal examination Ultrasonography Cystometry Cystocele Urinary incontinence Sensation of vaginal fullness Pain or urinary leakage during sexual intercourse Pelvic examination Voiding cystourethrography Drugs and substances Caffeine Alcohol Diuretics Urinary frequency in an otherwise healthy patient Empiric elimination of offending substance (to confirm that frequency resolves) Pregnancy 3rd trimester of pregnancy Clinical evaluation Prostatitis 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 Radiation cystitis History of radiation therapy of the lower abdomen, prostate, or perineum for treatment of cancer Clinical evaluation Cystoscopy and biopsy Reactive arthritis 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 wk after sexual contact STD testing Spinal cord injury or lesion Lower-extremity weakness, decreased anal sphincter tone, absent anal wink reflex Injury usually clinically obvious MRI of the spine Urethral stricture Hesitancy, tenesmus, reduced caliber and force of the urine stream Urethrography Urinary incontinence Unintentional passage of urine, particularly when bending, coughing, or sneezing Cystometry Urinary tract calculi Colicky flank or groin pain Urinalysis for hematuria Ultrasonography or CT of the kidneys, ureters, and bladder UTIs 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 STD = sexually transmitted disease.

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 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 GU 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; 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.

Red flags

The following findings are of particular concern:

• Lower-extremity weakness
• Fever and back pain

Interpretation of findings

Dysuria suggests frequency is due to UTI or calculi. Prior pelvic surgery suggests incontinence. Weak urine stream, nocturia, or both suggests 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 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

Treatment varies by cause.

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. UTI or use of diuretics may be a cause in both sexes.

Key Points

• UTI is the most common cause in children and women.
• Prostate disease is a common cause in men > 50 yr.
• Excessive intake of caffeine can cause urinary frequency in healthy people.

Last full review/revision September 2009 by Seyed-Ali Sadjadi, MD