What causes urinary urgency?

Causes of Urinary Urgency

Urinary urgency is primarily caused by overactive bladder (OAB), interstitial cystitis/bladder pain syndrome (IC/BPS), neurological conditions, bladder outlet obstruction, and overflow incontinence, with OAB being the most common etiology requiring targeted treatment based on the underlying cause.

Overactive Bladder (OAB)

• OAB is characterized by "urinary urgency, usually accompanied by frequency and nocturia, with or without urgency urinary incontinence (UUI), in the absence of urinary tract infection or other obvious pathology" 1
• Urgency is defined as the "complaint of a sudden, compelling desire to pass urine which is difficult to defer" and is considered the hallmark symptom of OAB 1
• OAB symptoms may occur during daytime, nighttime, or both, causing significant impact on quality of life 1
• Detrusor overactivity (DO) is a common urodynamic finding in patients with OAB, though not all patients with OAB symptoms demonstrate DO on urodynamic testing 1

Interstitial Cystitis/Bladder Pain Syndrome (IC/BPS)

• IC/BPS presents with "an unpleasant sensation (pain, pressure, discomfort) perceived to be related to the urinary bladder, associated with lower urinary tract symptoms of more than six weeks duration" 1
• While pain is the hallmark symptom of IC/BPS, urinary urgency is extremely common (84% of patients) 1
• The urgency in IC/BPS differs qualitatively from OAB urgency - IC/BPS patients typically void to avoid or relieve pain, whereas OAB patients void to avoid incontinence 1
• IC/BPS patients may experience a more constant urge to void compared to the classic OAB urgency 1

Neurological Causes

• Neurogenic bladder dysfunction can cause urgency through detrusor hyperreflexia in patients with:
  • Parkinson's disease - altered dopamine basal ganglia-frontal circuit that normally suppresses the micturition reflex 2
  • Spinal cord injuries - complete or incomplete suprasacral lesions leading to uninhibited or reflex bladder 3
  • Multiple sclerosis and other neurological conditions 1, 2
• Neurogenic disorders of lower urinary tract dysfunction may present with urgency and require specialized evaluation including post-void residual (PVR) assessment and complex cystometrography 1

Bladder Outlet Obstruction

• In men, benign prostatic hyperplasia (BPH) is a common cause of urgency due to:
  • Direct obstruction of urine flow 4
  • Secondary detrusor overactivity that develops in response to obstruction 4
• Urgency symptoms in men with BPH may coexist with weak urinary stream and incomplete emptying 4
• In women, pelvic organ prolapse or previous anti-incontinence procedures may cause obstruction leading to urgency symptoms 1

Overflow Incontinence

• Detrusor underactivity can lead to urgency and paradoxical incontinence due to:
  • Incomplete bladder emptying with elevated post-void residual (>250-300 mL) 5
  • Overflow episodes that may be mistaken for urgency incontinence 5
• Patients may experience hesitancy, dampness rather than soaking, and infrequent spontaneous voiding 1
• Impaired bladder sensation leads to storage of large urine volumes with subsequent urgency 1, 5

Other Causes

• Urinary tract infection - inflammation causes irritative voiding symptoms including urgency 1
• Bladder hypersensitivity - increased sensation of bladder filling at lower volumes 6, 3
• Mixed urinary incontinence - combination of stress and urgency incontinence mechanisms 1
• Medications - certain drugs may cause or exacerbate urgency symptoms 5
• Excessive fluid intake - polyuria can contribute to urgency symptoms 1
• Sleep disorders - conditions like sleep apnea can contribute to nocturia and associated urgency 1

Diagnostic Considerations

• Urgency is a subjective symptom that patients may describe differently - some use terms like "pressure" and may deny "pain" 1
• Research shows that patients can distinguish between "normal" urge to urinate and "urgency," suggesting urgency exists on a continuum rather than as an all-or-none phenomenon 7
• The absence of detrusor overactivity on a single urodynamic study does not exclude it as a causative agent for urgency symptoms 1
• Misdiagnosing overflow incontinence as OAB can lead to inappropriate treatment with antimuscarinics, potentially worsening the condition 5