Urinary retention is a common problem in older men but it also affects women. Acute retention is generally associated with a sudden inability to void and abdominal pain.
Acute painless urinary retention can be the first presenting symptom of a neurological problem and requires emergency referral. Haematuria or the presence of clots raises suspicion of urinary tract cancer.
Longstanding incomplete voiding of the bladder is termed chronic urinary retention. Often such patients are asymptomatic. It is important to be aware of complications, such as bladder overfilling, severe constipation or a UTI.
|Red flag symptoms|
In men, bladder outflow obstruction is the most common cause of acute and chronic retention, frequently due to prostactic enlargement.
Retention can also be precipitated by anticholinergic side-effects, especially in those who already have bladder outflow obstruction. Urethral stenosis can cause retention and may result from recurrent UTIs or from estrogen deficiency in postmenopausal women.
Retention can also arise after surgery for stress incontinence. Detrusor muscle failure is the most common cause of chronic retention in women and may be idiopathic or due to an underlying neurological problem.
In acute urinary retention the diagnosis is usually obvious.
The patient presents with sudden inability to void, with an enlarged tender bladder.
In chronic retention the clinical features are more variable and include nocturnal enuresis, recurrent UTIs, and lower urinary tract symptoms associated with bladder outflow obstruction, such as frequency, urgency, hesitancy and poor stream. Many patients are asymptomatic and this condition may just be picked up on incidental finding of an enlarged bladder.
The diagnosis of chronic retention requires a post-voiding urinary sensation scale and sometimes serial scans are necessary for confirmation.
In all cases of retention, urine analysis and renal function should be performed. Acute retention warrants urgent catheterisation and subsequent investigation.
Chronic retention requires urological referral if associated with an elevated creatinine. Catheterisation is not always necessary in chronic retention but is indicated if there is acute renal impairment or a large residual volume.
High pressure chronic retention can result in upper urinary tract damage and longstanding obstruction can damage the bladder. Long-term management of urinary retention may be surgical or medical depending on the cause and the patient's history.
- Dr Porter is a salaried GP in Rochford, Essex