When I am stressed, my teeth and gums hurt.

I don't usually have persistent tooth or gum pain. However, when I am stressed or tired, my teeth and gums inevitably hurt. In particular, there is overall pain around the molars on the upper left side. The pain lasts for a few days, but when the stress factors disappear or I get enough sleep, it gets better. I'm not sure if this is due to cavities or gum disease, or if it's simply fatigue or psychological issues. Does anyone else experience this?