Deviation of the nasal septum: Failure of the nasal septum to be in the center where it is supposed to be. (The nasal septum is the wall inside the nose that runs down the middle dividing it into two sides.)
Deviation of the nasal septum may be congenital (present at birth) or occur later from trauma. The major problem that it tends to cause is airway obstruction. Correction is by surgery.
