How the Urinary Tract Works
Female urinary tract
Male urinary tract
Normal vs. overactive bladder
The bladder and kidneys are part of the urinary system the organs in our bodies that produce, store and pass urine. You have 2 kidneys that produce urine. Then urine is stored in the bladder. The muscles in the lower part of your abdomen hold your bladder in place.
When it isn't full of urine, the bladder is relaxed. When nerve signals in your brain let you know that your bladder is getting full, you feel the need to urinate. If your urinary system is normal, you can delay urination for some time.
Once you are ready to urinate, the brain sends a signal to the bladder. Then the bladder muscles squeeze (or "contract"). This forces the urine out through the urethra, the tube that carries urine from your body. The urethra has muscles called sphincters. They help keep the urethra closed so urine doesn't leak before you're ready to go to the bathroom. These sphincters open up when the bladder contracts.
OAB can be caused by the nerve signals between your bladder and brain telling your bladder to empty even when it isn't full. OAB can also be the result of your bladder muscles being too active. Then your bladder muscles contract to pass urine before your bladder is full, and that causes a sudden, strong need to urinate. We call this "urgency."
Risk Factors for OAB
- As you grow older, the risk of OAB symptoms increases. But not all people will have signs OAB as they age. No matter what your age, there are treatments that can help.
- Overactive bladder and urine leakage are not “normal” or expected parts of the aging process.
- Just because you are getting older doesn't mean your OAB symptoms can't respond to treatment
- Both men and women are at risk for OAB. Women who have gone through menopause and men who have had prostate problems seem to be at greater risk for OAB.
- People with diseases that affect the brain or spinal cord, such as stroke and multiple sclerosis, are at high risk for OAB.