What causes upper respiratory infection and severe congestion?
Patient: I have an upper respiratory infection that seems to be lingering. I have been taking amoxicillin, 500mg. for 4 days. I do feel better but still have a lot of congestion. The nasal mucus has gone from being quite thin and clear to much thicker and greenish/yellow. I am concerned I am not getting rid of the infection. What do you think? Doctor: Respected user , hi I evaluated your query thoroughly.* Usually upper respiratory tract infections are airborne through atmospheric   bacteria / virus / pollens / tiny dust particles .* Recovery part depends upon the causative organisms , host immune    response , type of treatment , associated comorbid conditions etc.* Better to get consulting with your doctor to get early rid of infection &    congestion.Hope this clears your doubts.Thanks for using Health care magic & keeping trust in our medical services.Wishing you fast and speedy recovery.Welcome for any further issues.Regards dear take care.