Once it was a sweet, sickly smell. Other times it reminds me of a metalic odor
. Each time, I will be diagnosed with a sinus infection
, placed on anibiotics, and within a week, the smell will subside. One time last year, I resisted treatment and ended up with a severe infection that included fever, chills, etc., all related to the sinus infection. When I get this smell, now, it is an indication to me that I need to address the infection or suffer further consequences. Hope this helps.