I have grinding pain in the top of my stomach under the breast bone. It feels like someone is twisting it, causing pain and some nausea. What could be causing this?
You should definitely see a doctor about this. Angina is often described as a kind of tightening, squeezing pain under the breastbone, sometimes with nausea. It's not an uncommon condition at all; about 7 million Americans have it but it does indicate that the heart muscle is not getting as much oxygen as it should. There are other possible causes for this pain. Esophogeal problems and heartburn are two of them, but if you do have angina - which can be managed - you should find out about it. It can indicate that your arteries are becoming blocked - preventing normal amounts of blood from getting to your heart. Here's some more information on angina, as well as some information on reflux.
Enjoying Summer Despite Acid Reflux
10 Foods to Avoid with Acid Reflux