Urge incontinence is a sudden and strong need to urinate. You may also hear it referred to as an unstable or overactive bladder, or detrusor instability.
In a properly functioning bladder, the bladder muscle (detrusor) remains relaxed as the bladder gradually fills up. As the bladder gradually stretches, we get a feeling of wanting to pass urine when the bladder is about half full. Most people can hold on after this initial feeling until a convenient time to go to the toilet arises. However, if you are experiencing an overactive bladder and urge incontinence, the bladder may feel fuller than it actually is. This means that the bladder contracts too early when it is not very full, and not when you want it to. This can make you suddenly need the toilet and perhaps leak some urine before you get there.
Often, if you experience urge incontinence you will also have the need to frequently pass urine and may wake several times a night to do so (nocturia).
The cause of urge incontinence is not fully understood however it seems to become more common as we age. Symptoms may get worse at times of stress and may also be made worse by caffeine in tea, coffee and fizzy drinks or by alcohol.
Urge incontinence can be linked to stroke, Parkinson's disease, multiple sclerosis and other health conditions which interfere with the brain's ability to send messages to the bladder via the spinal cord. These conditions can affect a person's ability to hold and store urine.
Urge incontinence may also occur as a result of constipation (not being able to empty the bowel or having difficulty doing so), an enlarged prostate gland or simply the result of a long history of poor bladder habits. In some cases the cause of an over-active bladder is unknown.