Extra Spurt Of Air

[Bazile]

Why do you now and again automatically take a deep breath ?

Is it because the oxygen levels in the blood falls below a certain level and so the body automatically takes in a bit more than normally ?

[Clanad]

Actually, if you mean taking the occasional deep breath as in sighing, when resting or inactive, it's the bodies way of re-balancing of oxygen and carbon dioxide... one site says "...The researchers also found that breathing in the same state for too long can cause the lungs to stiffen and exchange oxygen and carbon dioxide less efficiently. So your body will occasionally throw in a good long sigh to loosen the lungs’ air sacs and relieve the diaphragm and other respiratory muscles. This is why sighing can create such an immense sense of relief that you feel it emotionally as well as physically..."

[Bazile]

Yep - A sharp breathing in and out .