Urine is a waste product made as the kidneys filter the blood. Each kidney (one kidney on each side of the abdomen) sends newly made urine to the bladder through a tube called a ureter. The bladder acts like a storage site for urine. It expands to hold the urine until a person decides to urinate.
Holding urine and maintaining continence requires normal function of these parts of the body as well as the nervous system. Also, a person must be able to sense, understand, and respond to the urge to urinate. The process of urination involves two phases: (1) the filling and storage phase and (2) the emptying phase. During the filling and storage phase, the bladder fills with urine from the kidneys. The bladder stretches as it fills with increasing amounts of urine. On average, a person senses the need to urinate when approximately 200 mL (7 ounces) of urine is stored in the bladder. A healthy nervous system responds to the stretching of the bladder by signaling the need to urinate, while also allowing the bladder to continue to fill.
Upon urination, the muscle holding the stored urine in the bladder (the sphincter muscle) relaxes, the bladder wall muscle (the detrusor) contracts, and urine passes from the bladder to the outside of the body through another tube called the urethra. The average person can hold approximately 350-550 mL (12-18 ounces) of urine in the bladder. The ability to fill and store urine properly requires a functional sphincter muscle to control output of urine from the bladder and a stable detrusor muscle. To empty the bladder completely, the detrusor muscle must contract appropriately to force urine out of the bladder and the sphincter must relax to allow the urine to pass out of the body.
Urinary incontinence occurs when there is involuntary loss of urine that is a hygienic or social problem to the individual. Some define urinary incontinence to include any involuntary loss of urine. There are six general types of incontinence: stress incontinence, urge incontinence, mixed incontinence, reflex incontinence, overflow incontinence, and functional incontinence. The treatment of urinary incontinence varies depending on the specific cause of incontinence.
| Printer-Friendly Format | | | Email to a Friend |
Get breaking medical news.
Exercise for Urinary Incontinence
Like millions, Mary Lou Retton has urinary incontinence. There are no medications but pelvic muscle exercises often help. See more WebMD Videos »
Urinary incontinence is a medical condition that has significant negative effects on quality of life and may cause social stigma, financial hardship, and associated medical problems.
|