Hello, is it possible to have asthma if you are at 100% oxygen? I've been felling short if breath that gets worse at night or walking. I also feel a tight chest not sure if it is my chest or my abdomen that feels tight since I've been diagnosed with acid reflux. My doc said I can't have asthma bc I am at 100% oxygen. However, I'm a little doubtful with her reasoning. I also have nasal congestion tho Nothing comes out and a bit of mucus buildup in my throat but it doesn't seem infection related since I always have it and it is not a lot/not a specific color. I have been told I have anxiety but I'm not sure if this is anxiety related bc I feel like it happens even when I'm not anxious.