If you have had a cold or sinus or ear infection recently, it could also be related to that. Or high blood pressure. I had it a few months ago. I googled it. Mine eventually went away by itself, but in between there i did go on antibiotics for some lung stuff. It has been a really rough summer for respiratory diseases, imo. I think i even bought a sinus inhaler, trying to break something thru. I used to overuse those back in the '70's