inflammation of the tissues in the sinuses [webmd.com] viêm xoang WebMD https://www.webmd.com/allergies/sinusitis#1. http://www.webmd.com/allergies/sinusitis [webmd.com] https://www.webmd.com/allergies/sinusitis#1 acute or chronic WebMD http://www.webmd.com/allergies/sinusitis sinus infection