Difficulty Urinating (Urinary Retention)

Difficulty urinating refers to a range of symptoms that make the act of voiding uncomfortable, inefficient, or impossible. At the most severe end of this spectrum lies urinary retention — the inability to voluntarily empty the bladder completely or at all. Urinary retention is classified as acute or chronic.

Acute urinary retention is a sudden, complete inability to void despite a full bladder. It is a painful urological emergency that causes increasing suprapubic discomfort and distension, and requires urgent catheter drainage. Chronic urinary retention is a more gradual, incomplete inability to empty the bladder, in which patients can still void but consistently leave a significant volume of urine behind (post-void residual). Chronic retention is often painless, which means it can persist for a prolonged period before being recognized — during which time it may cause progressive bladder damage and upper tract injury.

Between these extremes is a spectrum of voiding difficulties including hesitancy (difficulty initiating urination), a weak or slow urinary stream, straining to void, intermittency (stopping and starting of the stream), and terminal dribbling.

Urethral injury and urethral stricture

• Damage to the urethra from trauma causes scarring and narrowing of the urethra (urethral stricture). This is one of the most clinically important causes of voiding difficulty in younger men and is directly related to the conditions managed in the urology setting. Urethral stricture produces progressively worsening obstructive voiding symptoms and, in severe cases, acute urinary retention.

Benign prostatic hyperplasia (BPH)

• The most prevalent cause of voiding difficulty in older men. Gradual enlargement of the prostate gland compresses the urethra, causing progressive obstructive lower urinary tract symptoms. In the context of trigger events — including urinary tract infection, constipation, prolonged immobility, or the use of medications with anticholinergic or sympathomimetic properties — BPH can precipitate acute urinary retention.

Prostate cancer

• Advanced prostate cancer involving the bladder neck or urethra, or causing significant urethral compression, may produce voiding difficulty. 

Neurogenic bladder dysfunction

• Disorders of the nervous system that impair the coordinated neural control of the bladder and urethral sphincter — including spinal cord injury, multiple sclerosis, Parkinson's disease, stroke, and diabetic neuropathy — can cause either urinary retention or incontinence.

Post-operative urinary retention

• Urinary retention is a common complication following surgical procedures, particularly those involving the pelvis, spine, or lower extremity, and is related to the effects of anesthesia on bladder contractility, post-operative pain, opioid analgesia, and restricted mobility.

Medications

• Many medications can impair bladder contractility or increase urethral resistance, precipitating urinary retention. 

Constipation and fecal impaction

• Severe constipation — particularly fecal impaction — can physically compress the urethra and bladder outlet, precipitating acute urinary retention, especially in elderly patients.

See a physician if:

• There is increasing difficulty initiating urination, a noticeably weaker urinary stream, or the need to strain to void
• There is a persistent sensation of incomplete bladder emptying after voiding
• Urinary frequency (including nocturia) has increased gradually over weeks to months, particularly in a man over 50
• Difficulty urinating follows a urethral injury, pelvic fracture, or urological procedure
• Post-void residual urine has been measured as significantly elevated on imaging or bladder scanning

Seek emergency evaluation immediately if:

• There is a complete sudden inability to urinate despite the urge and a full, uncomfortable bladder — this is acute urinary retention and requires immediate catheter drainage
• Complete inability to urinate is associated with significant lower abdominal pain or distension
• Inability to urinate after trauma to the pelvis or perineum