[2] A deviated septum is an abnormal condition in which the top of the cartilaginous ridge leans to the left or the right, causing obstruction of the affected nasal passage.

It is common for nasal septa to depart from the exact centerline; the septum is only considered deviated if the shift is substantial or causes problems.

[3] Symptoms of a deviated septum include infections of the sinus and sleep apnea, snoring, repetitive sneezing, facial pain, nosebleeds, mouth breathing, difficulty with breathing, mild to severe loss of the ability to smell,[1][4] and possibly headaches.

[5] Only more severe cases of a deviated septum will cause symptoms of difficulty breathing and require treatment.

[7] A medical professional, such as an otorhinolaryngologist (ears, nose, and throat doctor), typically makes the diagnosis after taking a thorough history from the affected person and performing a physical examination.

A minor surgical procedure known as septoplasty can cure symptoms related to septal deviations.