Normal bladder function
Filling and emptying your bladder is a complex interplay of kidney function, nerve signals and muscle activity. A problem anywhere in this system can contribute to overactive bladder and urge incontinence.
The kidneys produce urine, which drains into your bladder. When you urinate (void), the urine passes from your bladder through an opening at the bottom (neck) and flows out a tube called the urethra (u-REE-thruh). In women, the urethral opening is located just above the vagina. In men, the urethral opening is at the tip of the penis.
As your bladder fills, nerve signals alert your brain and eventually you'll feel the need to urinate. When you urinate, nerve signals coordinate the relaxation of the pelvic floor muscles and the muscles of the urethra (urinary sphincter muscles). The muscles of the bladder tighten (contract), pushing the urine out.
Involuntary bladder contractions
Symptoms of an overactive bladder occur because the muscles of the bladder are starting to contract involuntarily. This contraction creates the urgent need to urinate.
Several conditions may contribute to signs and symptoms of overactive bladder, including:
- Neurological disorders, such as Parkinson's disease, strokes and multiple sclerosis
- High urine production as might occur with high fluid intake, poor kidney function or diabetes
- Medications that cause a rapid increase in urine production or require that you take them with lots of fluids
- Acute urinary tract infections that can cause symptoms similar to an overactive bladder
- Abnormalities in the bladder, such as tumors or bladder stones
- Factors that obstruct bladder outflow — enlarged prostate, constipation or previous operations to treat other forms of incontinence
- Excess consumption of caffeine or alcohol
Often, the specific cause of an overactive bladder isn't known.
Jan. 16, 2013
- Marinkovic SP, et al. The management of overactive bladder syndrome. BMJ. 2012;344:e2365.
- South-Paul JE, et al. Current Diagnosis & Treatment in Family Medicine. 3rd ed. New York, N.Y.: The McGraw-Hill Companies; 2011. http://www.accessmedicine.com/resourceTOC.aspx?resourceID=52. Accessed Dec. 19, 2012.
- Overactive bladder. American Urological Association. http://www.urologyhealth.org/urology/index.cfm?article=112. Accessed Dec. 19, 2012.
- What I need to know about bladder control for women. National Institute of Diabetes and Digestive and Kidney Diseases. http://kidney.niddk.nih.gov/kudiseases/pubs/bcw_ez/. Accessed Dec. 19, 2012.
- Ellsworth PI, et al. Frequently asked questions in the evaluation and management of overactive bladder. Journal of Family Practice. 2009;58(suppl):s1.
- Treatment of overactive bladder in women. Rockville, Md.: Agency for Healthcare Research and Quality. http://www.ahrq.gov/downloads/pub/evidence/pdf/bladder/bladder.pdf. Accessed Dec. 19, 2012.
- DuBeau CE. Clinical presentation and diagnosis of urinary incontinence. http://www.uptodate.com/index. Accessed Dec. 19, 2012.
- Urodynamic testing. National Institute of Diabetes and Digestive and Kidney Diseases. http://kidney.niddk.nih.gov/kudiseases/pubs/urodynamic/. Accessed Dec. 19, 2012.
- DuBeau CE. Treatment of urinary incontinence. http://www.uptodate.com/index. Accessed Dec. 19, 2012.
- Anger JT, et al. Outcomes of intravesical botulinum toxin for idiopathic overactive bladder symptoms: A systematic review of the literature. The Journal of Urology. 2010;183:2258.
- Lightner DJ (expert opinion). Mayo Clinic, Rochester, Minn. Dec. 21, 2012.
- Subak LL, et al. Weight loss to treat urinary incontinence in overweight and obese women. New England Journal of Medicine. 2009;360:481.
You Are ... The Campaign for Mayo Clinic
Mayo Clinic is a not-for-profit organization. Make a difference today.