There are four main types of bladder weakness:

Stress incontinence

This is the most common form of bladder weakness. Sufferers notice that a small amount of urine leaks during any physical activity that places increased pressure on the abdomen.

This leakage may occur when coughing, sneezing, laughing, lifting heavy objects or when participating in certain forms of exercise (e.g. high impact aerobics or jogging).

Stress incontinence is most common in women and is associated with pregnancy, childbirth, obesity and the menopause. In men, it may occur after surgery on the prostate gland.

Urge incontinence

Here, the bladder fills to a certain level and the accompanying pressure then causes a strong urge to urinate. This is followed by an uncontrollable tightening of the bladder, which then empties completely. If the person doesn't make it to the toilet in time, accidents will happen.

Urge incontinence may be caused by infections of the bladder (e.g. cystitis), neurological disorders (e.g. stroke or Parkinson's disease) or bladder stones. Tumours may also be responsible.

Overflow incontinence

This occurs when the bladder fills but because of an obstruction, such as an enlarged prostate gland, it can't empty normally. Once full, the bladder overflows and leaks small amounts of urine on an almost constant basis. This condition is rarely seen in women.

Mixed incontinence

Some people suffer from a combination of both urge and stress incontinence.