![Why is blood red?](https://tipsforwomens.org/wp-content/uploads/2023/10/Why-is-blood-red.jpeg)
You cut yourself and your blouse ends up stained red. This existential question then comes to mind: why is the blood this color? The response from Dr. Kierzek, medical director of TipsForWomens.
A mixture of plasma and blood cells, blood helps distribute oxygen to each part of the body and eliminate poisons and waste. It also transports nutrients to all tissues of the body and thus plays a role in digestion. But that doesn’t tell us why it has such a color? Why does blood wear such a pretty red dress? Answers.
Hemoglobin is responsible for the color of blood
If we wrongly think that blood is red because it contains red blood cells, this is not the case.
“It is hemoglobin that makes blood red… The iron it contains turns red on contact with oxygen“, notes Dr. Kierzek.
Interesting fact: blood displays different shades of red, depending on its oxygenation. The blood that comes from the heart is bright red while the old blood, depleted in oxygen and loaded with impurities, is rather dark.
On the other hand, although the veins may appear blue, they do contain red blood. It is the skin, acting as a “filter”, which gives – in appearance – a blue color to the circulating blood.