Viral sinus infection is more likely if symptoms last less than 10 days and start improving
Bacterial sinus infection is more likely if symptoms last more than 10 days without improvement
Bacterial sinus infection is more likely if symptoms get worse after initially improving
Bacterial sinus infection is more likely if you have severe symptoms such as high fever, thick yellow or green nasal discharge, and facial pain for at least 3 to 4 days
Viral sinus infection is more likely if symptoms follow a cold and are mild to moderate
Bacterial sinus infection is more likely if symptoms are one-sided and severe
Viral sinus infection is more likely if fever is absent or low-grade
Bacterial sinus infection is more likely if fever is higher and persistent
Viral sinus infection is more likely if symptoms gradually improve on their own
Bacterial sinus infection is more likely if symptoms persist or worsen despite supportive care