Yawning when yu are truly tired, is it different than a yawn that just happens
April 3, 2007 5:13am CST
like when you see someone else yawn, it makes you yawn. When I am really tired and I yawn, my jaw gets all tight and I grit my teeth. But when I am not tired and yawn, that never happens. So is it different than a yawn when I am not tired, or is it my body just reacting to the stress of the day?