Incontinence

Urinary incontinence is the involuntary loss of urine from the bladder. It is twice as common in women as in men. There are three main types of incontinence: stress continence, urge incontinence and overflow incontinence. Sometimes, a fourth type, called functional incontinence, is added.

1. Stress incontinence
   The most common form of urinary incontinence is stress incontinence. It occurs when there is a loss of urine during physical activity or exertion such as coughing, sneezing, laughing, exercise, or any other movements which put pressure on the bladder. Stress incontinence is often linked to weakness of the pelvic floor (Pic. 1), which normally supports the bladder and helps to close the urethra, especially in women. The amount of urine loss in stress incontinence is generally small. 
2. Urge incontinence
   Urge incontinence is the most common type of incontinence experienced by older people. It consists of a sudden and urgent desire to urinate and the inability to hold the urine until a toilet is reached. Urge incontinence is caused by an overactive bladder muscle, and is characterized by involuntary contractions. Urge incontinence is sometimes also referred to as overactive bladder or detrusor (the muscle in the wall of the bladder, responsible for its emptying) instability.
3. Overflow incontinence
   Overflow incontinence occurs when the bladder cannot empty completely. This results in an bloated bladder and eventually the muscles near the urethra and anus will open causing urine to leak. This can be caused by a compression of the urethra from the outside, or by poor control of the bladder. Women with overflow incontinence may only have a weak dribbling stream of urine or feel that they need to empty their bladder but cannot. Similar symptoms are common in men with benign prostatic hyperplasia (Pic 2). In women, overflow incontinence may be caused by uterine tumours, but is generally rarer. The residual urine in the bladder can cause recurrent bladder infections.
4. Functional incontinence
   Functional incontinence is a form of urinary incontinence in which a person is usually aware of the need to urinate, but for one or more physical or mental reasons they are unable to get to a bathroom. The loss of urine can vary, from small leakages to full emptying of the bladder.

Incontinence may be associated with several diseases including: 

Pelvic floor dysfunction

Pelvic floor dysfunction refers to a wide range of issues that occur when muscles of the pelvic floor are weak, tight, or there is an impairment of the sacroiliac joint, lower back, coccyx, or hip joints. Symptoms include pelvic pain, pressure, dyspareunia (painful sexual intercourse), incontinence, incomplete emptying, and gross organ protrusion. Tissues surrounding the pelvic organs may have increased or decreased sensitivity or irritation resulting in pelvic pain. When the tissues of pelvic floor do not sufficiently help to close the bladder, stress incontinence may manifest itself in situations with increased pressure in the bladder. In women, physical changes resulting from pregnancy, childbirth, and menopause often contribute to stress incontinence. The condition affects up to 50% of women. 

Pelvic organ prolapse

Pelvic organ prolapse, or sometimes uterine prolapse, is characterized by descent of female genital organs beyond their normal anatomical confines, and is closely linked to dysfunction of the pelvic floor. The condition usually occurs when the pelvic floor collapses as a result of childbirth or heavy lifting which can tear soft tissues. Once the pelvic floor is weakened, the bladder also descends, allowing for stress incontinence in situations with increased intraabdominal pressure.

Benign prostatic hyperplasia

Enlarged prostate is a common cause of overflow incontinence in men. The compressed urethra
does not enable complete emptying of the bladder, leading to its distension with retained urine and subsequent leakage.

Prostate cancer

Tumorous growth in the prostate may cause overflow incontinence in a manner similar to benign prostate hyperplasia, although it is less common, as prostate cancer does not usually affect the parts of the prostate bordering the urethra. Treatment of prostate cancer by prostatectomy (surgical removal of the prostate) may in turn lead to damage to pelvic tissues, leading to stress incontinence, which is otherwise rare in men.

Uterine fibroids

In women, large uterine fibroids may compress the urethra from outside and lead to overflow incontinence.

Endometrial cancer

Among patients treated for endometrial cancer, more than half of them suffer from stress incontinence. It is probably caused by damage to pelvic floor by the curative surgery, or post-operative radiotherapy, or a combination of both therapeutic methods.