WHy do people Yawn?

To express their sleepy feeling and to remove abit of their stress.

Thats what I too wanted to know. People say, when are bored, you will yawn. Someone say when you feel sleey you will yawn. Scientifically someone say, you grab more oxygen when you yawn and you can keep sleep at bay.

I have read about it and there is some science behinf it ...I guess They say that you will yawn when your body needs some extra oxygen reseves when they are tired. I'm not entirely sure, but I do know for a fact that it is not neccessarily know why people yawn.

I do know that when a room builds up in carbon dioxide, a lot of people in the room, the carbon dioxide causes you to become sleepy and you begin to yawn even if you are not tired. It would seem to me that yawning is the streching of the neck and head muscles in order for the veins to constrict and move blood more rapidly to the brain. So hypoxia of the brain or carbon dioxide would trigger it.

yes i feel yawning is contagious...and it happens wen someone around u yawns..and i have read this in some article...but dont know the exact reason...may be because wen u see someon ywan...ur nerves feel lazy too..and it performs yawning...

Yawn.. every people do it.. maybe because they are sleepy.. lol.

I think it happens when we get really tired. I think it is a sign for our body to go to bed.

It's the body's way of getting more oxygen into your system when it's low. You take a deep breath when you yawn, filling your lungs and getting more oxygen into your bloodstream. That's why it happens when you're tired, it's the body's way of trying to get more oxygen to the brain to wake you up.