While urinary incontinence isn’t an inevitable part of ageing, the prevalence does increase in line with age.
How the bladder works
The bladder is a balloon-shaped organ – a muscle in fact -- that sits in the pelvis, supported and held in place, by the pelvic floor muscles. Its purpose is to store and release urine.
A tube, called the urethra, connects the bladder to the genitals, from where the urine is passed. Ring-like muscles, called sphincters, control the urethra, keeping it closed so urine doesn’t leak from the bladder before it’s ready to be released while hormones help keep the lining of the bladder and urethra healthy.
The bladder muscle relaxes when it fills with urine and contracts when it’s time to urinate. Nerves carry signals from the bladder to the brain – to let the brain know when the bladder is full - and from the brain to the bladder – to let the bladder know when it’s time to urinate.
For the urinary system to do its job effectively, muscles and nerves must work together to hold urine in the bladder and then release it at the right time. If either the muscles or the nerves are impaired, this could lead to incontinence.
- Weak muscles
Weak pelvic muscles cause most bladder control problems. If the bladder sags out of position, it can stretch the opening to the urethra.
- Nerve damage
Damaged nerves can either send signals to the bladder at the wrong time, meaning the bladder pushes out urine without warning, or send no signals at all, so the brain can't tell when the bladder is full. Nerves can be damaged by diseases or trauma. Diseases and conditions that can damage the nerves include diabetes, Parkinson's Disease, multiple sclerosis and strokes.
As well as weak muscles and nerve damage, bladder control problems can be caused when medicines dull the nerves.
Different types of incontinence
Incontinence is generally categorised as:
- Functional Incontinence
Patients with functional incontinence have mental or physical disabilities that keep them from urinating normally, although the urinary system itself is structurally intact. Conditions that can lead to functional incontinence include Parkinson's Disease, Alzheimer's Disease and other forms of dementia.
- Urge incontinence
People that leak urine after a strong, sudden urge to urinate, have urge incontinence. It’s caused by over activity of the bladder muscles and can be caused by a range of conditions like mental stress, nerve damage (from diabetes, a stroke, an infection, or another medical condition), infections, tumours or bladder stones. A thorough assessment of the underlying causes is, therefore, essential for treatment. Urge incontinence often starts with the consistent urge to urinate although the urine can be held. It progresses to the point where the urge cannot be controlled any longer. Urge incontinence can be treated with medication that helps regulate the activity of the bladder as well as exercises, to strengthen the pelvic floor muscles and bladder training for the extension of urination intervals to aid improved bladder capacity and reduced frequency.
- Stress incontinence
As many as 1 in 5 women over the age of 40 have some degree of stress incontinence*. This is when urine leaks when they cough, laugh, sneeze or exercise -- or when there is pressure on their abdomen. It is almost exclusively present among women but is not linked to age - a lot of young women and professional athletes are prone to this condition. Stress incontinence isn’t related to emotional stress, rather a weakening of the pelvic and sphincter muscles. When these are weak, any sudden pressure can push urine out of the bladder. Pelvic floor exercises and strengthening of the pelvic muscles can help.
- Overflow incontinence
Overflow incontinence is particularly common among elderly men. The cause, in most cases, is a confinement of the urethra due to an age-related enlargement of the prostate. This condition is called benign prostatic hyperplasia (BPH) or benign prostatic hypertrophy. As the prostate enlarges, it can squeeze the urethra and affect the flow of the urinary stream. The lower urinary tract symptoms (LUTS) associated with the development of BPH rarely occur before the age of 40, but more than half of men in their sixties, and up to 90 percent of men in their seventies and eighties have some LUTS. Through the blockage of the urethra, the urine is stowed in the bladder and gradually overstretches the bladder muscle. Symptoms vary, but the most common ones involve changes or problems with urination, such as a hesitant, interrupted, weak stream; urgency and leaking or dribbling; more frequent urination, especially at night; and urge incontinence. Problems with urination do not necessarily indicate blockage caused by an enlarged prostate. Treatment includes the removal of the blockage via surgery, intermittent bladder depletion via catheterisation or prostate resection.
- Mixed Incontinence
Mixed incontinence refers to a combination of stress and urge incontinence. Many patients experience symptoms of both types. A thorough examination of the causes is essential for effective treatment.
* (National association for continence (NAFC) (2010)