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Why It Isn't Easy Being Blue

Can you actually turn blue from holding your breath for a long period of time? Why It Isn't Easy Being Blue on today's Moment of Science.

As you already know, we get our color from the pigments in our skin and from the red blood flowing underneath it. When the oxygen levels in our blood drop, that blood turns a darker shade of red. Now, if you hold your breath long enough so that the oxygen level in your blood drops to about 80 percent of what it normally is, you'd start looking bluish. This is due to the way our tissues absorb and reflect back light.

Obviously, you can't hold your breath long enough for your oxygen levels to drop to the required level. You'd pass out long before the oxygen level in your blood dropped low enough to make you turn blue. And at that point, you'd automatically start breathing again. Death has a different affect on the color of the skin.

When you die and your blood stops circulating, it settles down in the blood vessels and moves to the lowest point in the body. So if you're lying down, it'll settle down to your back and drain out of your face. This will make you appear pale and chalky.

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