Why is it that pee yellow not purple?

The color of urine is primarily determined by the concentration of a pigment called urobilin, which is produced during the breakdown of hemoglobin in red blood cells. Urobilin is a yellow-orange pigment, and its concentration in urine varies depending on factors such as hydration level, diet, and overall health.

Purple urine is uncommon, and it is typically caused by certain medications or medical conditions. For example, some antibiotics, such as rifampin, can cause urine to turn a reddish-orange or purple color. Other medications that can cause purple urine include phenazopyridine (Pyridium) and some chemotherapy drugs.

Certain medical conditions can also affect the color of urine. For example, porphyria, a group of rare disorders that affect the production of heme (a component of hemoglobin), can cause urine to appear purple or reddish-brown. Beetroot (red beets) can also turn urine a reddish or purplish color, but this is not a cause for concern.

If you notice a significant change in the color of your urine, especially if it is accompanied by other symptoms such as pain, fever, or difficulty urinating, it is important to talk to your doctor to determine the cause and receive appropriate treatment.