Recently had 2 episodes of feeling suddenly dizzy and slight nausea. Both times were indoors in AC environment. 1st time was 2 days ago while eating dinner at a restaurant -occurred suddenly mid meal -steak, potato, broccoli & carrots; was sipping on a frozen sangria margarita -about 1/2 way empty and was the only alcohol drank that day. this morning again happened -had only drank the usual 2-3 cups of morning coffee, but had not ate any thing so sat down and ate a tangerine and a banana -felt only slightly better. Then ate a few crackers and felt much better. I have had basic screens for diabetes and low thyroid done -have come back normal. Are these symptoms consistent with a stomach ulcer? Other thoughts