When we're in a heightened state the accompanying thoughts and sensations can be alarming, but they can't hurt you and aren't any danger. They don't lead to anything, no disasters or catastrophes, so it's good to keep reminding yourself of this. The only way you might faint is from the same things that might make anyone faint, like if you stopped eating and had very low blood sugar, or a drop in blood pressure perhaps. I would talk to your doctor about any concerns you have about possible side-effects and have any necessary checks to help ease your mind.