Is it true that we yawn when our brains are deprived of oxygen? Most of us can feel a yawn coming on. The muscles in our jaw begin to tighten, our nostrils might flare, and our eyes might tear up as ...

Humans’ first experience with yawning happens in utero, says Matthew D. Epstein, M.D., associate medical director of the Atlantic Health Sleep Centers in New Jersey. Yet, Earth-side, the ...

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 ...