Bladder

What and where is it?

The bladder is a hollow, muscular, balloon-shaped organ in the pelvis, between the hip bones, that stores urine. It is part of the urinary system.

What it does

• A reservoir for urine: its walls stretch as it fills, and a normal bladder holds about 1.5 to 2 cups.
• Signalling: it sends signals to the brain as it fills.
• Emptying: its wall muscle tightens and pushes urine out through the urethra.
• Preventing leaks: the two sphincters keep the urethra closed between visits to the toilet.

How it works

1. 1
   From the kidneysThe ureters carry urine from the kidneys to the bladder.
2. 2
   FillingIts walls stretch and the internal sphincter stays closed.
3. 3
   SignalThe brain learns that the bladder is filling.
4. 4
   UrinatingThe brain relaxes the sphincters, then tightens the bladder wall muscle, and urine leaves through the urethra.

Common problems that affect it

Infection and inflammation

• Cystitis: inflammation of the bladder, often from an infection. See urinary tract infections.
• Interstitial cystitis: a long-term problem causing bladder pain and frequent, urgent urination.

Control problems

• Urinary incontinence: loss of bladder control.
• Overactive bladder: the bladder squeezes urine out at the wrong time.

Other problems

• Bladder cancer.
• An enlarged prostate can cause a feeling that the bladder has not fully emptied.

Tests used to study it

A doctor can look inside the bladder with a cystoscopy:

• EndoscopyProcedure

Keeping it healthy

• According to NIDDK, most healthy adults should aim for six to eight 8-ounce glasses of fluid a day, at least half of it water. Needs differ for people with kidney stones, kidney failure or heart disease, so ask a clinician.
• Don't hold urine too long: it can weaken the bladder muscles and make complete emptying harder, and leftover urine can let bacteria grow.
• Empty the bladder fully without rushing, urinate after sex, and for women, wipe from front to back.
• Pelvic floor (Kegel) exercises strengthen the muscles that support the bladder, in both men and women.
• Keep your bowels regular with fibre and physical activity, cut back on caffeine and alcohol, and don't smoke; according to the CDC, quitting smoking lowers the risk of bladder cancer.
• Tell a health professional about any change: urinating more often, leaking, trouble starting, or a feeling that the bladder has not emptied.