The nasal septum is made of cartilage, and divides the nose into two separate chambers.
A deviated septum is an abnormal configuration of the cartilage that divides the two sides of the nasal cavity, which may cause congestion, problems with proper breathing, or nasal discharge. Estimates are that 80 percent of all nasal septums are off-center. A deviated septum is when the septum is severely shifted away from the midline.
The most common symptom from a deviated septum is difficulty breathing through the nose. The symptoms are usually worse on one side, and in some cases the drainage of the sinuses is curtailed and results in repeated sinus infections. A deviated septum may be present at birth, caused by an injury, or result from damage from previous medical treatments.