Passing urine

Urine is produced by the kidneys and collected in the bladder, which expands like a balloon as the volume increases. When full, the bladder empties to the outside through the urethra.

Most people need to pass water every three to four hours during the day and up to once or twice in the night. For normal urination, the muscular wall of the bladder has to contract at the same time as a valve mechanism at the outlet of the bladder relaxes. Most incontinence in adults results from problems with one or other, or a combination, of these processes.

Symptoms and causes

Stress incontinence

This causes urine to leak when there is an increase in pressure from within the abdomen such as when coughing, sneezing, laughing or carrying heavy weights. It develops when the normal control mechanism for keeping the outlet of the bladder closed is weakened. This can happen when the urethra moves out of the normal position (prolapses), as it can when the pelvic floor muscles are weakened. Stress incontinence is much more common in women than men and can be triggered by childbirth, hysterectomy and the menopause.

Urge incontinence

With this type, there is a strong urge to pass frequent, small amounts of urine. This is caused by the muscle of the bladder wall – known as the detrusor muscle - being overactive. This means it contracts to squeeze out urine before the bladder is completely full.

Urge incontinence can also be caused by a bladder infection. Diabetes can also cause excessive production of urine and very frequent trips to the toilet.

Mixed incontinence

Some women get both urge and stress incontinence. The two may or may not be linked.

Overflow incontinence

This happens when urine held by the bladder builds up to the point where the bladder can no longer expand. It can be caused by an obstruction in the urinary tract or damage to the nerves that supply the bladder.

Other causes of incontinence:

• Medication - The side-effects of some drugs for high blood pressure such as prazosin and doxazosin, and muscle relaxants like diazepam can include incontinence.
• Problems with the urinary system such as fistulas (abnormal openings between the ureter, urethra or bladder into the uterus or vagina), and bladder stones.

How do I know if I'm incontinent?

If you regularly pass urine accidentally – for example when you cough or have a full bladder, or just leak for no reason, you may well have incontinence. Although many people try to manage on their own – often because it's a source of embarrassment – medical advice should be sought sooner rather than later, as help is available.

What will my doctor want to know?

•  the length of time incontinence has been a problem,
• the time of day leakage occurs,
• whether there is any pain passing urine,
• the number of times urine is passed in 24 hours,
• whether coughing, sneezing, etc. causes a leak,
• if you have an urgent need to go, or go frequently,
• what, if any, medicines you are taking,
• if the problem is getting worse,
• what affect it is having on your life.

To make it easier to answer these questions, it's a good idea to keep a record over the seven days before the consultation. Make a note of the amount of urine passed, the time of day and whether leakage has occurred.

Routine tests

A sample of urine (mid-stream urine, or MSU) is examined for signs of infection, bladder stone or other abnormalities.