Why Is Pee Yellow?


Peeing or Urinating, though a basic bodily function that everyone gets to enjoy, is not exactly the hottest topic around a dinner table. Before you could barely open your eyes you were taking part in the spectacular waste management process that ends with peeing. This essential process is grotesque and taboo to many which is why it remains a ponderable mystery to this day. Lets break down the porcelain barrier that shrouds peeing and figure out the origination of that sunny glow.

Peeing is the result of a complex process that starts in the cells that make up your body. The cells create “garbage” just like you might in your home. The urination process is the work of the heart, kidneys, and bladder primarily. These organs use the blood in your body to pick up the garbage and get rid of it by way of your pee.

Why Is Pee Yellow?

Folks in the middle ages were partially in agreement that there was actual gold in pee. Needless to say that it was someone’s job to harvest people’s pee and extract the riches from it. Too bad that turned out the be false. Imagine how easy it would be to find a bathroom if there was gold in your pee. You would have food carts on the street converted into urinals and shops would invite everyone who entered to pop a squat. Anyone who has ever tried to find a bathroom in a busy city knows how wonderful that could be.

Gold is not responsible for the yellow color in pee. It is actually the work of chemicals called Urobilins. These chemicals start out as worn out red blood cells. The hemoglobin from these cells is broken down into a substance called Bilirubin. Bilirubin becomes part of the process in the liver, gall bladder, intestines, and ultimately ends up as poo (feces).

Not all of it ends up there however. Some remains in your blood and is removed by your kidneys where it is converted to Urobilins and it is that substance that creates that golden hue. So there you have it. A susbtance that was forgot by #2 so it ended up going with #1 creates the color that is synomous with that yellowy garbage collection service known as pee.

Ironically, the yellow toned urobilins also cause the the coloration of bruises!

Diagram from the Cleveland Clinic on Pee Color

Credit: Cleveland Clinic

Random Facts about Pee

  • Anything besides yellow pee can mean something is wrong. If you have brown, orange, or black pee see a doctor immediately)
  • Many color variations come from what you eat. (Asparagus, Fava Beans, Carrots, Beet, Blackberries, Rhubarb, etc)
  • The urea from urine is a very popular component of fertilizer.
  • Urine can ultimately be broken down and oxidized into a component used to make gun powder



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