What causes urinary urgency?

Causes of Urinary Urgency

Urinary urgency—defined as a sudden, compelling desire to urinate that is difficult to defer—stems from multiple distinct pathophysiologic mechanisms, with overactive bladder (detrusor overactivity), bladder outlet obstruction, interstitial cystitis/bladder pain syndrome, neurological disorders, and urinary tract infections being the primary causes. 1

Primary Urological Causes

Overactive Bladder (OAB)

• OAB is characterized by urinary urgency as its hallmark symptom, typically accompanied by increased daytime frequency and nocturia, with or without urgency urinary incontinence, occurring in the absence of urinary tract infection or other obvious pathology. 1
• Detrusor overactivity (DO)—involuntary bladder muscle contractions during filling—is a common urodynamic finding in OAB patients, though importantly, not all patients with OAB symptoms demonstrate DO on testing. 2, 1
• The absence of detrusor overactivity on a single urodynamic study does not exclude it as the cause of urgency symptoms, as technical limitations may prevent eliciting DO even in highly symptomatic patients. 2
• The mechanism involves abnormal bladder smooth muscle contractions that increase urgency and frequency of both incontinent episodes and voluntary urination. 3

Bladder Outlet Obstruction (BOO)

• In women, pelvic organ prolapse or previous anti-incontinence procedures (such as mid-urethral slings) can cause obstruction leading to secondary urgency symptoms. 1
• Refractory urgency symptoms developing after bladder outlet procedures should prompt evaluation for BOO, as elevated detrusor voiding pressure with low flow suggests obstruction, particularly with new-onset storage or emptying symptoms post-surgery. 2
• In men, benign prostatic hyperplasia (BPH) causes bladder outlet obstruction that produces urgency, nocturia, and weak urinary stream in up to 40% of men over age 50. 4

Overflow Incontinence/Detrusor Underactivity

• Detrusor underactivity leads to paradoxical urgency and incontinence due to incomplete bladder emptying with elevated post-void residual (>250-300 mL). 1, 5
• Impaired bladder sensation allows storage of large urine volumes, which subsequently triggers urgency as the bladder becomes overdistended. 1
• This is a critical diagnostic pitfall: misdiagnosing overflow incontinence as OAB can lead to inappropriate antimuscarinic treatment, potentially worsening urinary retention. 1, 5

Pain-Associated Causes

Interstitial Cystitis/Bladder Pain Syndrome (IC/BPS)

• IC/BPS presents with unpleasant bladder-related sensations (pain, pressure, discomfort) associated with lower urinary tract symptoms lasting more than six weeks. 1
• While pain is the hallmark of IC/BPS, urgency occurs in 84% of patients, but the quality differs from OAB urgency. 1
• Patients with IC/BPS void to avoid or relieve pain, whereas OAB patients void to avoid incontinence—this distinction is diagnostically crucial. 1, 5

Infectious and Inflammatory Causes

Urinary Tract Infection (UTI)

• Bladder inflammation from UTI causes irritative voiding symptoms including urgency. 1
• Recent evidence suggests that a significant proportion of OAB patients have active bladder infection, with pathogenic bacteria and increased bladder inflammation found more frequently in OAB patients than controls. 6
• In women with persistent urgency/frequency and negative standard urine cultures, probative treatment with doxycycline (including treatment of the sexual partner) resulted in symptom resolution or improvement in 71% of cases. 7

Neurological Causes

• Neurogenic disorders of lower urinary tract dysfunction (such as spinal cord injury, myelomeningocele, multiple sclerosis) may present with urgency and require specialized evaluation. 1
• These patients require post-void residual assessment and complex cystometrography during initial evaluation and ongoing follow-up to assess for upper tract complications. 2

Systemic and Non-Urological Causes

Sleep Disorders and Cardiovascular Conditions

• Sleep-disordered breathing (including obstructive sleep apnea) can contribute to nocturia and associated urgency symptoms. 2, 1
• Cardiovascular conditions causing nocturnal polyuria may present with urgency predominantly at night. 2

Excessive Fluid Intake

• Polyuria from excessive fluid intake can contribute to urgency symptoms by overwhelming normal bladder capacity. 1

Mixed Urinary Incontinence

• A combination of stress and urgency incontinence mechanisms occurs when both sphincteric incompetence and detrusor overactivity coexist. 1
• In mixed incontinence, urodynamic studies may help with symptom correlation, though they may not precisely predict treatment outcomes. 2

Critical Diagnostic Considerations

Before attributing urgency to OAB, clinicians must systematically exclude:

• Urinary tract infection (via urinalysis and culture) 5
• Overflow incontinence (via post-void residual measurement) 5
• Bladder outlet obstruction (via pressure-flow studies if indicated) 2
• Pain-predominant conditions like IC/BPS (via careful symptom characterization) 5

The cornerstone of evaluation is a bladder diary, which documents frequency patterns, voided volumes, and timing of symptoms to distinguish small-volume voids (typical of OAB/IC/BPS) from large-volume voids (suggesting polyuria). 2, 5