A muscular balloon that stores urine from the kidneys and signals the brain as it fills.
Urine color
Pale straw usually reflects good hydration; B vitamins (riboflavin) can make it bright yellow harmlessly.
When to get help
Pain or burning when urinating, blood in urine, or fever need medical attention.
Evidence & sources
Riboflavin supplements can turn urine bright yellow; this is harmless. Evidence: established. Known: Excess riboflavin is excreted in urine. Unknown: โ Source: NIH Office of Dietary Supplements, Riboflavin โ Health Professional Fact Sheet (Current revision).