I Have Long-standing Allergies. I Am Female, 73, In Good

I have long-standing allergies. I am female, 73, in good health generally. In the past few years, I've had six or eight episodes of severe shortness of breath that lasts usually a day or two. My doctor says my lungs and bronchial tubes are clear. He diagnosed an upper respiratory viral infection. I don't disagree but don't think that explains my restricted breathing, especially when I move around even a moderate amount. I can hardly walk to the mailbox and back without panting and wheezing.