I grind my teeth at night and have done so for many years. i use a custom fit night mouth guard to help protect my teeth. all of a sudden i'll wake up with severe tooth pain. is this infection or is this my teeth shifting. no redness of gums?

It is not feasible to provide a meaningful opinion without additional history, physical examination and may be some tests. It would be prudent to see a dentist. Wish you good health!

Since you have been grinding for years, you have worn away the enamel on your teeth causing sensitivity Your bite has changed causing pressure on other teeth. Have you had x-rays recently? You may need a new night guard? All of these scenarios could contribute to your pain, so see your dentist.

Sudden tooth pain may indicate need for adjustment or replacement of orthotic, damage to one or more teeth, and or damage to surrounding tissued. We all have a whole new skeleton every 7-8 years, and teeth supporting bone adapts to changes in stress. You will have to be examined by your Dentist to determine cause and thus appropriate treatment.