Updated February 12, 2015.

Definition: Inflammation of the sinuses usually caused by bacterial or viral infections. Acute sinusitis is the sudden onset of symptoms including facial pain, green nasal discharge and fever. Chronic sinusitis is characterized recurrence of acute sinusitis of or by infections that lasts several weeks to months, with more mild symptoms of nasal congestion, post-nasal drip and dull headaches.

Also Known As: sinus infection