In the last 10 months, I ve had 3 occasions where I ve started out with an extremely sore throat, that after a day or two turns into head congestion, coughing, running nose (sporadically) and just overall crappy feeling! I m in Korea, so I think it may allergy related to the dust coming from China. I m not in Seoul, but 50 miles south, so I don t think smog is the problem, but then again, who knows?