What is Stress Urinary Incontinence?
Urinary incontinence is the involuntary loss of urine from the body. It affects over 13 million Americans, 85% of whom are women. Urinary incontinence that occurs with straining or with activities is known as stress urinary incontinence (SUI). It can develop slowly as you age or may be a result of a specific event such as childbirth. It can also occur with chronic or repetitive straining such as coughing or high-impact aerobic activities. Regardless of cause, it generally occurs when your pelvic muscles are no longer strong enough to keep the opening from the bladder neck closed when you are under physical stress.
Examples of this physical stress include:
- Entering/exiting a vehicle
- Sexual intercourse
- Increasing abdominal pressure in any other way
How Does Stress Urinary Incontinence Occur?
To help you better understand incontinence, here is some basic information about your urinary system.
The urinary system works with your brain and spinal cord to coordinate urinary functions.
Your kidneys filter blood and dispose of liquid waste products in the form of urine. Urine is carried out of the kidneys by the ureters and into the bladder, which is a muscle-lined bag that acts as a reservoir. Urine is stored in the bladder until the brain sends a signal for it to empty. The bladder is connected to the urethra by the bladder neck.
When your urinary system is functioning normally, you can control when to hold or release your urine. When your bladder becomes full, it sends a signal to your brain. When you are ready to urinate, your brain sends a message to the bladder and urine will be released into the urethra. The urethral sphincter muscle, which surrounds the urethra, opens and closes the bladder neck. It will voluntarily contract to temporarily hold urine, or release itself to let urine flow down the urethra and out of your body.
Damage, weakening or injury to the muscles supporting the urethra can result in Stress Urinary Incontinence. This occurs when weak pelvic floor muscles, especially at the bladder neck opening, cannot reflexively tighten during times of increased pressure on the bladder and the urethra. This leads to involuntary urine loss.