A nasal obstruction is anything that impedes the flow of air into and out of the nose. The obstruction may block one or both of the nasal passages.
Most cases of nasal obstruction are temporary, caused by sinusitis, allergies, birth control medication, or overuse of nasal sprays. The blockage may also be caused by an anatomical factor, such as a deviated septum, enlarged adenoids, nasal polyps, turbinate bones, or foreign objects.
If the nasal obstruction appears to coincide with a certain time of year, it may be caused by an allergy, such as to pollen. If the blockage appears to be on only one side of the nose, then an anatomical cause is more likely. Snoring is often a symptom of an anatomical cause for a nasal obstruction.
Avoidance of an allergen, if the cause is allergic, can help alleviate symptoms. if the cause of the obstruction is anatomical, surgery is usually required.