Why do people grind their teeth at night ?

Hi everyone,

My boyfriend recently has noticed at different times I have been grinding my teeth at night !

To my knowledge I have just been doing this recently and I don’t know why…. Could it be perhaps due to anxiety ? My boyfriend sleeps over when he notices it, could it be because of him ? How can I stop ?

Or is it totally something else ? (I have an appt with my dentist later, just wanted to ask on here first)