Deviated septum is a condition wherein the nasal septum is displaced to one side, which makes one nasal passage smaller than the other; resulting to the septum positioned significantly off-center leading to reduce air flow because one side of the nose is blocked.

Nasal speculum is used by the doctor to examine the inside of the nose which can reveal a deviated septum at the same time determine the severity of the condition.

Medications often prescribed by the doctor may include decongestants, antihistamines, and nasal cortisone sprays to reduce the risk of nasal blockage; however these are only temporary solutions. Septoplasty is the surgical procedure that is proven effective in repairing a deviated septum wherein a surgeon carries out the procedure by cutting and removing some portions of the septum before repositioning in the proper position.

Obstruction in one or both nostrils can make breathing with the nostrils difficult especially in the presence of colds and allergies causing swollen and narrowed nasal passages. Because of the blockage, nasal congestion, nosebleeds, recurring inflammation of the sinusitis, and noisy breathing when sleeping is also common.

Deviated septum can be caused by faulty fetal development and can be present at birth (congenital). It can also be caused by injury to the nose that caused displacement of the nasal septum including accidents in sports, automobile accidents, and injury inflicted by human.