WE all have our theories about why we yawn – boredom, the brain getting oxygen, or the most obvious one, lack of sleep. There ...

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 ...

(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 ...

(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 ...

Need a lot of caffeine to get through the day? What about yawning a lot? These signs of sleepiness may be a red flag, according to researchers, and could harm your long-term health.

(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 ...