I'm a 47 year old healthy female who was recently treated for a UTI. I believe the medication given, Macrobid, I had a reaction to. I passed out for no apparent reason. With shallow breathing afterward I was urged to go to the E.R. They did a chest x-Ray, electro cardiogram, took blood and everything came back fine. A test for sepsis came back negative. Since then I have had the same feeling of passing out. It's worse in the morning but I just had an episode this evening while sitting in a comfortable chair with my feet outstreatched on an ottoman. I frequently feel warm sensations in both arms and in the back of my head and feet. Of course I panic making things worse, then I feel jittery, start shaking and get cold. What do the warm sensations indicate? I tried to analyze how I felt before the fainting episode and its like I'm buzzed and can't focus, I feel queezy then the panic sets in. Help!