Best medical practices seek to apply the best available scientific evidence to clinical decision making. In utilizing evidence-based medicine, one seeks to assess the strength of medical evidence to guide the diagnosis and treatment of disorders. Evidence of clinical efficacy is ranked double-blind, placebo-controlled clinical trials to clinical wisdom. The former is the most likely to yield a consistent result whereas the latter may be dependent on a skilled expert, but not necessarily reproducible. In addition, the skilled clinician recognizes that not all treatments may be solely evaluable by vigorous statistical analysis.

Each side of the facial skeleton has four sinuses, named by the facial bone in which they occur. The frontal sinuses are located within the frontal bone, or forehead. The ethmoid sinuses develop within the ethmoid bones, which are between the nose and eyes. The maxillary sinuses form within the maxillary bones, or upper jaw, and the sphenoid sinuses are within the sphenoid bone.

Viruses are the most common cause of acute sinusitis and may lead to secondary bacterial infections. Other causes of sinusitis are allergies, which can cause swelling or obstruction of the sinus drainage pathways into the nose, and genetic disorders such as cystic fibrosis. The latter leads to an impairment of the cilia, or hair cells which direct the transport of mucous produced within the sinuses into the nose. This physiologic process is known as mucociliary transport and is essential for the normal cleansing of the sinuses of infectious agents and air pollutants.