Urinary retention

Being unable to empty the bladder. Acutely it is agonising; chronically it is painless and destroys kidneys quietly.

What it is

Urinary retention means being unable to empty the bladder properly. It comes in two forms and they behave completely differently.

Acute retention is sudden and painful. The bladder fills, cannot empty, and the pain is severe. It is one of the commonest urological emergencies and it needs catheterisation urgently.

Chronic retention is the dangerous one, because it is often painless. The bladder never empties fully, residual volume climbs over months, pressure backs up to the kidneys, and the first sign may be kidney failure or overflow incontinence that gets treated as ordinary incontinence.

Causes include benign prostate enlargement, constipation, medication with anticholinergic effects, neurological conditions, and after surgery or anaesthetic.

Signs you might notice

Acute: unable to pass urine at all, severe lower abdominal pain, a visibly distended bladder, distress and agitation.

Chronic: a poor stream, feeling of incomplete emptying, frequent small volumes, waking repeatedly at night, and leaking, particularly overnight.

In someone who cannot report it: new agitation, restlessness, confusion, or a change in behaviour. Retention is a classic and commonly missed cause of delirium.

Retention with back pain and leg weakness or saddle numbness is cauda equina syndrome and is a surgical emergency.

How it can affect day-to-day life

Anticholinergic medication is a leading avoidable cause. Some antidepressants, antihistamines, bladder antimuscarinics and cold remedies all contribute, and in an older man that combination plus constipation is a common route into an emergency admission.

In care settings, checking the bladder should be a routine part of assessing new confusion or agitation, and it frequently is not.

Chronic retention is under-diagnosed because nobody scans the bladder in somebody who is not complaining.

Supporting someone well

Scan or palpate the bladder in anybody with new confusion, agitation or distress. It takes a minute and it finds a treatable cause.

Treat constipation, which both causes and worsens retention.

Review medication for anticholinergic burden.

Watch after any surgery or anaesthetic, which commonly precipitates it.

Use double voiding and unhurried, private toileting.

Do not assume overnight leaking is simple incontinence in an older man; it may be overflow.

Get acute retention relieved urgently; it is painful and it damages kidneys.

Recognise the cauda equina red flags and treat them as an emergency.

Where to get help

Acute retention needs urgent same-day assessment, usually A and E.

A GP can arrange a bladder scan and blood tests for kidney function in suspected chronic retention.

Retention with back pain, leg weakness or saddle numbness is a 999 or immediate A and E matter.