Let's start at the beginning. Who yawns? Everybody. Not just people, but cats, dogs and fish do, too! What is a yawn? It is an involuntary action during which you open your mouth and breathe deeply ...

ATLANTA — Find yourself yawning a lot? Do you need that third or fourth cup of coffee to make it through the afternoon at work? Such signs of sleepiness may be a red flag of a serious sleep deficit ...

Yawning is often seen as a simple sign of fatigue or boredom. However, this natural and universal reflex could reveal much more about your hormonal health—particularly your levels of cortisol, the ...

Yawn. Nice nap? After Thanksgiving dinner, I mean. This holiday got me to wondering about why we yawn. And guess what? We don't know. Yep, the whole yawning thing appears to be a big mystery to ...

Yawning—such an odd physiological phenomenon. Humans yawn, and so do dogs, monkeys, birds, and just about every known vertebrate species other than giraffes (yes, that is also odd). Over a decade ago, ...

(CNN) — Find yourself yawning a lot? Do you need that third or fourth cup of coffee to make it through the afternoon at work? Such signs of sleepiness may be a red flag of a serious sleep deficit that ...