I have been feeling nauseous for over a week. also very tired and my stomach feels tight. what could be causing this?

Nausea: I assume that you are not pregnant. Your continual stomach symptoms may be due to inflammation the stomach lining(gastritis) or they could be related to stress or intolerance to a medication or other substance. If symptoms don't resolve by following a bland,low fat diet and avoidance of alcohol,caffeine and nicotine, see your Physician for a thorough evaluation which includes tests for liver dis