Urinary retention: symptoms, causes, catheters and treatment

Urinary retention is the failure of the bladder to empty. The Bladder & Bowel Community explains that the bladder is a balloon-shaped hollow muscle designed to stretch as it fills and contract as it empties, and that urinary retention is the bladder not emptying properly, which leaves residual urine.

A UK clinical reference article (Patient.info professional reference, hosted by the Surrey and Sussex ICB clinical resource) distinguishes two forms. Acute retention is sudden and usually painful. Chronic retention develops slowly, and the article notes that an acute episode can occur on top of chronic retention, for example when an enlarged prostate has been causing relatively painless obstruction.

The article lists the symptoms of acute urinary retention as being unable to pass urine, a strong urge to pass urine, a tender and distended bladder and general uncomfortableness. A full bladder can be felt as a tender swelling in the lower tummy.

The Bladder & Bowel Community says symptoms of retention that develops more slowly are not always obvious and may include hesitancy (having to strain to pass urine), strong urgency and frequency with only a small amount coming out, and a weak, intermittent urinary stream. It warns that while the bladder is not emptying properly, the residual urine can become infected.

The NHS enlarged prostate page says to ask for an urgent GP appointment or get help from NHS 111 if you cannot pee at all. The clinical reference article describes acute retention as usually painful and requiring emergency treatment with a catheter, so sudden inability to pass urine should not be left to settle on its own.

The clinical reference article stresses that rarer serious causes such as cauda equina or spinal cord compression must not be missed. The NHS back pain advice says to call 999 or go to A&E if you have back pain and numbness or loss of feeling around your genitals or anus, changes in your bladder or bowels such as difficulty peeing, or weakness or numbness in both legs.

The Bladder & Bowel Community says there are two main causes: obstruction to the flow of urine through the urethra, and a weak bladder muscle. It says the most common cause of difficult urination in men is a blockage from an enlarged prostate, and that for women one common cause is an anterior (bladder) prolapse that can distort the urethra and restrict flow. The clinical reference article says that over five years, about 10% of men over 70 and close to a third in their 80s will develop acute retention.

The article says up to 10% of acute urinary retention episodes are thought to be attributable to drugs. It lists those known to increase the risk: anticholinergics (for example some antipsychotic and antidepressant medicines and anticholinergic respiratory medicines), opioids and anaesthetics, alpha-adrenoceptor agonists, benzodiazepines, non-steroidal anti-inflammatory drugs, detrusor relaxants, calcium-channel blockers, antihistamines and alcohol.

It also lists precipitants clinicians ask about, such as recent surgery, urinary tract infection, constipation, a large fluid intake, cold exposure or prolonged travel. Do not stop a prescribed medicine on your own; if you notice difficulty passing urine after starting one, tell your prescriber or pharmacist promptly.

The clinical reference article says acute retention is about ten times more common in men than in women. In women it lists prolapse, a pelvic mass such as a fibroid or ovarian cyst, a retroverted gravid (pregnant) uterus, vulval or vaginal inflammation, and sphincter problems among the causes.

It also lists postpartum complications, with an increased risk after instrumental delivery, prolonged labour and caesarean section, and notes that retention is often seen after surgery. The NHS says a catheter may be used to drain the bladder during childbirth if you have an epidural anaesthetic. If you cannot pass urine after having a baby, tell your midwife or GP straight away.

The article describes a history, an abdominal and genital examination, a rectal examination to check the prostate and exclude faecal impaction, and a neurological examination to look for spinal causes. Investigations include urinalysis, blood tests including kidney function and glucose, and ultrasound, which can measure the urine left after passing water and look for kidney swelling.

Depending on the suspected cause, CT scans, MRI of the brain or spine, cystoscopy or urodynamic studies may follow. The Bladder & Bowel Community lists urinalysis, uroflowmetry, urodynamics and cystoscopy as tests that may be recommended, and suggests keeping a bladder diary for a few days before an appointment.

The article says initial management is immediate and complete bladder decompression, and that NICE recommends men with acute urinary retention are immediately catheterised, with an alpha-blocker offered before the catheter is removed. For retention caused by prostate enlargement, a trial without catheter (TWOC) has become standard practice, and an alpha-blocker beforehand significantly increases the chance of success.

Treatment of other causes depends on the cause: treating infection or constipation, reviewing medicines, or addressing a prolapse or pelvic mass. The article lists complications including urinary tract infection, acute kidney injury and bleeding in the urine after rapid emptying of the bladder, which is usually self-limiting.

The NHS enlarged prostate page says that if symptoms are not causing many problems doctors usually recommend lifestyle changes first, and that medicines such as tamsulosin, doxazosin or alfuzosin may be offered for moderate or severe symptoms.

The NHS describes a urinary catheter as a flexible tube used to empty the bladder and collect urine in a drainage bag, usually inserted by a doctor or nurse, either through the urethra or through a small opening in the lower tummy (a suprapubic catheter). There are two main types: intermittent catheters, which are inserted temporarily and removed once the bladder is empty, and indwelling catheters, which stay in place for days or weeks and are held by a balloon.

The NHS says indwelling catheters are more convenient but more likely to cause infections, that the longer a catheter is used the greater the risk, and that other problems include bladder spasms, leakage, blockage and damage to the urethra. It says you should be able to live a relatively normal life with a catheter, including working, exercising, swimming and having sex. The Bladder & Bowel Community says some people are taught to carry out intermittent self-catheterisation at intervals set by their healthcare professional.

Acute urinary retention is an emergency handled through GP out-of-hours, A&E or an acute urology service on the NHS, which provide catheterisation, tests and a plan for a trial without catheter. Chronic symptoms are usually assessed through a GP and a urology or continence service.

Once the emergency has passed, private urology can offer quicker prostate assessment, flow tests and discussion of surgical options. Ask for a clear explanation of the cause, what happens if the trial without catheter fails and the risks of each option, and make sure your GP receives the plan.