question: For the past month, randomly, my heart beats harder than usual and faster. It continues to do so for hours. I was diagnosed with mild asthma when I was 15, I m 20 now, but I also smoke a lot, daily. I m not sure if any of those play into account but, I keep having to take really deep breaths to feel like I m getting enough oxygen and it s extremely worrying when I m just relaxing and I can feel it almost fighting for hours. What could this be and what should I do??