If you’ve been tired all day maybe you slept like crap last night you have probably been yawning a lot. But why do we yawn? It actually has a pretty functional purpose for your head. Think of it as air conditioning for your brain. It’s a way for your body to cool things down up there and increase the blood flow in hopes to make you more functional.
It doesn’t have to always been when your tired either. It may be from being stressed or bored as well.
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