what are sinus infections
Sinusitis, also known as a sinus infection or rhinosinusitis, is inflammation of the sinuses resulting in symptoms.Common signs and symptoms include thick nasal mucous, a plugged nose, and pain in the face.inusitis (or rhinosinusitis) is defined as an inflammation of the mucous membrane that lines the paranasal sinuses and is classified chronologically into several categories: 1  Acute rhinosinusitis â A new infection that may last up to four weeks and can be subdivided symptomatically into severe and non-severe.