about every 4 or 5 months, I wake up w/a severe sinus headache, usually i can drink a cup of coffee and eat a small bowl of cereal before I take some tylenol sinus med., soon after I have severe vomiting and pain all over my face and forehead, it last atleast 30 minutes, i get real cold, the pain is intense in my sinuses.....then I have to lay down for hours and feel groggy when I wake, usually this seems to happen during season changes.