Cortisol is a stress hormone that keeps us awake and active throughout the day. Normally, its levels drop in the evening.

When your baby isn't sleeping well, you're not sleeping well. What's worse, there's a somewhat cruel side effect that comes with having an exhausted baby: A sleep-deprived infant is actually less ...

It typically happens to babies and young children: they become “overtired” and cannot sleep, often because they have been awake too long. But adults can become overtired too, robbing them of ...