It can also happen as a complication from another viral, allergic, or fungal infection. In many cases, an underlying issue causes a buildup of fluid or air in your sinus cavities. This fluid or air ...
Sinus infection (sinusitis) is an infection that occurs in the sinuses, which are air-filled spaces lined with mucous membranes in the forehead, cheeks, and around your nose. Sinusitis occurs when ...