Thank you for your response. I should have mentioned that my father had hypertrophic cardiomyopathy. I have never had cardiac issues, though I am not sure if this should be of concern. I will see my PCP if my the shortness of breath does not improve within the next few days. Also, is it possible that a virus could cause this? I started feeling sick about a week ago, but I upped my Vitamin C significantly to 1000mg/day and got a lot of rest. The respiratory issue is the only thing that I have been experiencing since I initially started feeling sick.