This common condition is a misalignment of the nasal septum (the thin wall of bone and cartilage that divides the nostrils). Ideally, the septum is straight and positioned exactly in the center of the nose. However, in many cases it is positioned slightly off center and may also be crooked or misshapen.
A deviated septum may develop in the womb, or may occur during the trauma of the birth process. It can also occur later in life as the result of an impact to the side of the nose.
Symptoms of a deviated septum may include blockage of one or both nostrils, noisy breathing, sinus infections, nasal congestion, and nosebleeds. Symptoms may become more noticeable when the person has a cold.
Mild cases of deviated septum typically require no treatment. But if the deviation is severe, or if the deviation causes problems, it can be corrected with a procedure called a septoplasty.