If you have a chronic sinus infection that doesn't clear up within a couple of weeks, only then will most doctors take samples from your mouth/throat and nose for analyis.
There are three major possibilities: bacterial infection, viral infection or fungal infection. Then within each, there are potentially hundreds of different types and strains. Your meds will depend on what is causing your infection.
Most chronic sinus infections are caused by bacteria [staph or strep] which usually need a few months of antibiotic therapy. |