How nasal function influences the eyes, ears, sinuses, and lungs.

The nose is an integral part of the upper airway and the first contact of the body with inspired air. It is located in close proximity to several related airway structures that include the ears, paranasal sinuses, and eyes. It is also closely linked to the lower airway. Multiple lines of evidence support a close interaction and influence of the nose on these contiguous and distant organs via neural reflexes and systemic inflammatory processes. These interactions are reviewed in light of existing evidence.