Ever noticed the way your sweetly sleeping baby will suddenly sigh like the weight of the world rests on his tiny shoulders?

Of course, he isn't really sighing over his tough life-he's just taking an extra-deep breath. In fact, infants do this a lot more than adults, about once every few minutes.

Deep breaths help a baby's lungs work properly by opening small airways. Most of the time these airways work just fine, but occasionally (and this is normal in infants) a few of the very smallest need extra help to stay open. Sighs provide this little boost and make breathing easier. So when you hear your baby sigh, that just means his body's taking care of itself. Starting at a few months he'll need those deep breaths, and long sighs, less often.