What makes people yawn other than when there tired?
When you are tired all the systems in your body begin to work slower. One of the systems that slows down is your respiratory system. You begin to intake less oxygen because your body is beginning to think that you are going to sleep. Since you are not sleeping and still walking around you are consuming just as much oxygen. Your brain senses the low oxygen content and makes you yawn. When you yawn you intake a good chunk of oxygen.
It can be from boardom, after eating, getting sleepy. Some persons who are on medications for certain conditions do get to yawn alot. I am on Syntroid for my thyroids and I yawn alot. In many cases it could be hunger. Because the body needs to replenish, rest, and restore energy after work, exercise, or when you have been reading too long, the body tells you when to stop for a minute or so and do something else to refresh.
