multiple things can trigger it.. sometimes certain meds will trigger it for me, other times it comes out of the blue and I never figure out why I am getting it! .. as for heartburn, the best thing would be might be to try to take some Gaviscon before bed (that's what my doc has recommended.. I take prescription Prevacid every day). Also, I sleep with a wedge pillow which helps elevate me and minimize heartburn. I would try taking the Gaviscon or some other antacid before you go to bed for a few nights and see if it helps.. certainly won't hurt!