What is acute sinusitis?

What is acute sinusitis?

Acute sinusitis is a short-term inflammation of the sinuses, most often including a sinus infection. (Sinusitis is also known as rhinosinusitis because the swelling almost always includes nasal tissue as well as sinus tissue.) The sinuses are four paired cavities (spaces) in the head. They are connected by narrow channels. The sinuses make thin mucus that drains out of the channels of the nose, cleaning the nose. Typically filled with air, the sinuses can become blocked by fluid and swell from irritation. When this happens, they can become infected.