Urinary incontinence occurs when the normal process of storing and passing urine is disrupted. This can happen for a number of reasons.
Factors leading to the development of urinary incontinence in women
- vaginal birth. Giving birth vaginally may be associated with stress incontinence.
- heavier birth weight. Having a child or children who was/were heavier than normal.
- number of children. Giving birth to a high number of children.
- family history. There may be a genetic link to urinary incontinence, particularly stress incontinence.
- increasing age. Urinary incontinence becomes more common on reaching middle age and is most common in women over 70 years of age.
Causes of stress incontinence
Stress incontinence occurs when the pressure in the bladder, as it fills with urine, becomes so great that the urethra is unable to stay closed.
The urethra may not be able to stay closed if the pelvic floor muscles are weak or damaged. Any sudden extra pressure on the bladder, such as laughing, sneezing, can then cause urine to leak out of the urethra.
Causes of urge incontinence
This urgent and frequent need to pass urine is caused by contractions of the muscles in the bladder wall, known as the detrusor muscles. The detrusor muscles relax to allow the bladder to fill with urine, than contract when going to the toilet to let the urine out.
Sometimes the detrusor muscles contract too often, creating an urgent need to go to the toilet. This is called detrusor overactivity.