Urinary Retention

Key facts

• Urinary retention is the inability to fully or partially empty the bladder, ranging from chronic difficulty to sudden, complete acute retention.
• In men, an enlarged prostate pressing on the urethra is the most common cause; in women, pelvic organ prolapse or surgical scar tissue can narrow the outlet. Nerve damage from diabetes or spinal injury also disrupts bladder signaling.
• When poor bladder muscle contraction is the cause rather than a blockage, bethanechol stimulates the bladder wall directly to help it empty.
• Sudden, painful inability to pass urine at all is a medical emergency and needs immediate hospital care.

Why the bladder stops emptying

The most common cause in men is an enlarged prostate pressing on the urethra. In women, pelvic organ prolapse or scar tissue from surgery can narrow the outlet. Nerve damage from diabetes, spinal injury, or certain medications, particularly antihistamines and some antidepressants, can also disrupt the signals that tell the bladder muscle to contract. Older adults are affected more often, though anyone can develop it.

Relieving retention with medication

Where the cause is poor bladder muscle contraction rather than a physical blockage, medicines that stimulate the bladder wall directly can help. Bethanechol works this way, prompting the detrusor muscle to contract more forcefully so the bladder empties properly. It's one of the options covered under bladder health. When a blockage such as an enlarged prostate is the cause, treatment usually targets that underlying problem instead of stimulating the muscle.

When to seek urgent care

Acute urinary retention, a sudden, complete inability to pass any urine along with a painful, distended abdomen, is a medical emergency. Go to a hospital without delay. Chronic retention with no pain can still cause kidney damage over time if left untreated, so persistent difficulty emptying the bladder deserves a medical assessment even without severe symptoms.

This page is educational and does not replace advice from a doctor or pharmacist who knows your health history.