Why do we yawn? Yawning is a universal gesture. Everyone yawns, from babies still in their mother's womb to the elderly.

DEAR DOCTOR K: I get plenty of sleep. So why do I yawn all the time? DEAR READER: We all yawn frequently, more often in the early morning and late evening. Does it mean we're tired? Bored? Short on ...

Open your mouth wide, stretch the muscles of your jaw and upper body, take a slow breath in, and then exhale quickly. What have you done? You have yawned. Many animals, including humans, yawn. They do ...