What is a Sinus Infection?

Sinus infections (also known as sinusitis) usually follow a viral infection. Adults and children alike usually experience at least two or three viral infections a year. Often viral colds or upper respiratory infections are followed by a common cold and will usually clear up on their own. After a week of having cold symptoms a viral infection can turn into a bacterial infection. When the mucus from your nasal discharge changes from clear to yellow or green , it usually indicates a bacterial infection has developed.