So for the past couple of days I have a constant smell of smoke in my nose. I don't smoke, and I can't even think of the last time that I was around someone who smokes. I'm worried that this is a symptom of a brain tumor! When I go to smell a candle or perfume, they smell normal and fine to me - they smell like they should, but when I'm not actively "smelling something" - I smell smoke. Could this be some type of sinus infection? I have no mucus in my nose and throat, if there is some, it's very dry. Could this be from dry air? We live in a very dry climate. I also want to note that we live about 5000 ft above the closest town, so when I was driving home from town today, my nose sort of "popped" a few times like your ears do when you're reaching high elevation. Our ears normally pop a few times on the drive up or down, but today my nose did it too inside the left nostril.