This document discusses various types of acute rhinosinusitis. It defines acute rhinosinusitis as lasting less than 4 weeks with complete resolution of symptoms. The most common types are described as acute viral rhinosinusitis, acute bacterial rhinosinusitis, acute maxillary sinusitis, acute frontal sinusitis, and acute ethmoid and sphenoid sinusitis. For each type, the causes, symptoms, diagnosis, and treatment options are outlined. Complications are also discussed if the infections are not properly treated.