Has anyone with Sjogrens experienced mild dehydration? Over the last week, when I wake up my mouth is extremely dry,I am weak, light headed and my heart pounds with any kind of exertion at all. Once I drink some water, the symptoms go away until the next morning. About 4 years ago, I was hospitalized for Acute Renal Failure due to dehydration so I know what I am feeling is due to dehydration. Also, I have high blood pressure but now my BP is low. Not dangerously low but really low for me. I am really confused on what is causing this all of a sudden. I haven't changed any kind of medications and I drink tons of water during the day.