Hypotension and Dehydration

I have suffered intermittantly for about 7 years (with occurances of 1-2 times per year) of a condition that sounds like some of the entries posted on hypotension.  

My symptoms start with a sharp pain in my stomach, usually progress on to diarrhea, and to a feeling of lightheadedness, tingling in my arms and feet (sometimes feels like they are vibrating), cold extremities, pale complexion, and also aches in my arms (muscular aches).

The condition seems related to times when I am working hard and under stress, during which times my consumption of coffee and other diuretics is up and water consumption down.

I had one severe case in which I fainted.  In that case, I was taken to an emergency room and the docs suggested my problem was dehydration.

I am wondering if dehydration alone is a reasonable diagnosis, or if I should be checking for something else, and if so, how I should approach the testing.

I am otherwise in good health.  BP in exams has tended to be 110/70 to 120/80.  Had Lyme disease about a year before these symptoms started (with headaches and joint pain).

[Cleveland Clinic, MD]

Dehydration is in the differential diagnosis but with such vague symptoms there could be lots of different things going on.  I would recommend a good internal medicine consult perhaps at a University medical center.  Good luck.