I have had a series of passing out episodes. I have had heart and baarain checked out and the found nothing wrong. I live stress free, like my job, and cannot think of why this would happen. I have always had severe reactions to cigarette smoke , chalk dust, fermaldehyde, and other chemicals. Stated rotataing aspirin and Advil for arthritis. Wondering if aspirin could cause passing out. Its the one thing i changed because advil all the time lost its effectiveness. They did find low thyroid. Still adjusting it - only on lowest dose.