Re: Why does your face turn blue when you hold your breath

The answer to your question is very simple, its just a lack of oxygen. While I've never actually seen anyones face turn blue, on television and in movies they talk about how when someone is strangled or otherwise cut off from air their faces turn blue. This is because blood becomes deoxygenated (which is a blueish-purple color) which can then be seen through the delicate skin in thier face. This is why your lips turn a blueish color when you are cold. Cold weather causes vasoconstriction which is just a fancy word meaning your blood vessels get smaller in an effort to attempt to keep the blood warm. Your lips then lose some of thier blood supply which in turn will cause them to appear blue. When you are outside for a period of time and are cold your lips will turn blue and often the tip of your nose as well, however as soon as you step into a heated environment your blood vessels vasodialate which causes a rush of blood back to those areas and thats where we get the rosy cheeks and nose after being outside in the cold.