The answer depends on whether the incontinence is temporary (short-term) or chronic (ongoing). Common reasons for temporary incontinence include urinary tract infection, a medication side effect, drinking too much caffeine or alcohol, and delirium. When the situation changes or is treated, the incontinence tends to end quickly. These same situations can also exacerbate chronic incontinence.
The five most common causes of bladder incontinence in women over age 50 are:
This kind of incontinence -- by far the most common type affecting women -- occurs when pressure (the "stress" in its name) is put on the abdomen, such as when sneezing, coughing, getting out of bed or a chair, laughing, or doing some kinds of exercise. The neck of the bladder and the urethra fail to close properly, due to some kind of structural weakness, and the pressure pushes urine out of the bladder. (People with strong muscles can withstand the extra pressure and therefore aren't incontinent.)
Many women first experience stress incontinence after childbirth, when the pelvic floor muscles that support the bladder neck and urethra are stretched and weakened. If it doesn't clear up on its own and is left unaddressed, the problem can persist for years.
Then at menopause, the tissues that line the urethra can thin due to a loss of estrogen, and bladder and urethral sphincter muscles weaken. Someone who's had colorectal surgery or a full or partial hysterectomy is also at higher risk.
Urge incontinence (also called overactive bladder) is a sudden, strong need to urinate before the leakage.
Nerve damage (from injury or a nerve disorder such as Parkinson's disease) is a common cause. The nerves may send wrong information to the brain about when the bladder needs to "go." Urge incontinence may also be the result of some other medical condition, such as stroke, diabetes, infection, or a tumor blocking nerve signals. However, in most chronic cases, no specific cause for the urge incontinence can be found.
In this situation, the person has normal bladder control, but physical limitations impair the ability to use a toilet promptly. For example, the person may have arthritis or Parkinson's disease, which makes it difficult for them to move quickly and efficiently. People suffering from dementia (such as Alzheimer's disease) may have incontinence if they forget or don't notice their need to go to the bathroom.
In overflow incontinence, the person never feels the urge to urinate and the bladder simply keeps filling, until small amounts literally overflow the bladder and leak out.
In some cases caused by nerve damage, the brain receives no messages that bladder is full until it's too late. In other cases, the cause is an obstruction of the bladder outlet due to a prior surgery or prolapse.
Many older people have a combination of types of incontinence, such as stress incontinence with urge incontinence, or urge incontinence with functional incontinence.