Psalm 150:6 "Let every thing that hath breath praise the LORD. Praise ye the LORD."
As we all know, coughing is a reflex that clears our breathing passages from secretions, irritants, foreign particles and even microbes that might make us sick. We also know that sneezing is a reflex that cleanses our nasal cavity by forcefully expelling foreign particles and irritants. But why do we sigh? Is it just because we're exasperated or surprised?
Well, here's a surprise for you. Though you aren't even aware of it, you take a deep breath – that is, you sigh – about 12 times every hour. As researchers have discovered, we sigh about every five minutes to keep our lungs functioning properly.
In fact, if we didn't sigh, we would die. Researchers from UCLA and Stanford call sighing "a life-sustaining reflex that prevents air sacs located in the lungs, called alveoli, from collapsing." Study co-author Jack Feldman told LiveScience, "A human lung has as much surface area as a tennis court, and so that's all folded inside your chest." If humans didn't sigh about every five minutes, the alveoli would not be able to reinflate, causing the lungs to fail. The only way to pop alveoli open again is to take a deep breath.
Now remember that sighing is just one of thousands if not millions of vital processes going on inside your body all the time. If your body was lacking even one of those vital processes, you'd be in big trouble. So the next time you sigh, thank Your all-wise Creator!