Toothaches, of course, can cause an enormous amount of pain - causing enormous. There does appear to be some connection between stress and stroke, perhaps because stress can increase blood pressure and cholesterol - both of which increase one's risk of having a stroke.
Toothaches can also signal an infection which has a pretty easy into your system - causing further stress.
Clearly it's best to take care of toothaches early and properly before they become too painful and before your teeth harbor a substantial infection. Good luck!