The bladder and how it works Reviewed by Mr Chris Dawson,
consultant urological surgeon What is urine? Urine is a fluid
that contains: - urea – a by-product formed when the body breaks
down protein - other waste products You produce between two and
three pints of urine a day. The actual amount depends on how
much you eat, drink and sweat, and whether you're taking
medication such as diuretics (water tablets). Your urinary
system Urine drains from your kidneys to your bladder through
tubes called ureters. Your bladder is the hollow muscular organ
that stores your urine. It’s a bit like a floppy balloon – as
your bladder fills, it expands to store the urine. On average,
your bladder can hold 400 to 600ml of urine for up to about five
hours. The muscle in your bladder wall is called the detrusor
muscle. The detrusor muscle relaxes to allow your bladder to
fill. When you go to the toilet, it contracts to squeeze out
urine. Did you know? The female urethra is shorter than the male
urethra. This is why women are mo