Urinary Incontinence is the involuntary loss of urine from the bladder.
Urination is a complex activity. The bladder is a balloon-like organ that lies in the lowest part of the abdomen. The bladder stores urine that is produced by the kidneys and is transported to it by the ureters.  Urine is released through the urethra which carries urine to the outside of the body. Urination requires integrated activity involving nerves, muscles, the spinal cord, and the brain.

The bladder has two types of muscles: one is a muscular sac that stores urine and squeezes to empty.  The other is a circular group of muscles at the bottom or neck of the bladder that automatically stay contracted to hold the urine in and automatically relax when the sac contracts to let the urine into the urethra. In males, an enlarged prostate may interfere with the passage of urine. Another group of muscles below the bladder (pelvic floor muscles) can be trained to contract to hold urine within the body.

In a continent individual, as the bladder fills the brain receives messages from the expanding bladder and begins to send messages to the bladder to keep it from automatically emptying.  When continent, a person is able to control the time and the place to void.

Types Of Urinary Incontinence

Stress Incontinence:  A small amount of urine (less than a few tablespoonfuls) leaks from the bladder when the person laughs, coughs, lifts objects or runs.

Urge Incontinence:  Immediate loss of a moderate amount of urine caused by involuntary bladder contractions. Overactive Bladder (OAB) may lead to Urge Incontinence.

Mixed Incontinence: Small to moderate amounts of urine are lost with this combination of stress and urge incontinence.

Overflow Incontinence: Leakage of a moderate amount of urine when the amount of urine produced is larger than the storage capacity of the bladder.

Functional/Environmental Incontinence: Incontinence is caused by factors other than the bladder.  Factors might include difficulty walking or inadequate vision to get to the toilet.

What about Bedwetting?
Experts do not know what causes nighttime incontinence (nocturnal enuresis). Young people who experience nighttime wetting are typically physically and emotionally normal. It is thought that most cases probably result from a mix of factors including slower physical development, an overproduction of urine at night, a lack of ability to recognize bladder filling, difficulty in waking from a deep sleep and in some cases anxiety. Research has shown there is a correlation between a family history of bedwetting and an individual’s bedwetting suggesting that nocturnal enuresis may be inherited.

Information Resources:
National Association for Continence:  www.nafc.org
Simon Foundation for Continence: www.simonfoundation.org
National Kidney and Urologic Diseases Information Clearinghouse: www.niddk.nih.gov