What causes a blocked nose?
Nasal obstruction can be due to problems with the shape of the inside of the nose, or swelling of the lining of the inside of the nose. Problems with the shape of the inside of the nose can be due to twisting of the middle partition of the nose (the nasal septum), or to weakness of the outside of the nose.
Either of these may be associated with abnormalities of the shape of the outside of the nose. Occasionally other structures, such as the adenoids, can be enlarged leading to nasal obstruction.
The nose is lined by a thin mucous membrane which can swell to cause blockage. Folds of the mucous membrane called turbinates are particularly prone to swelling. We all experience this swelling in response to the common cold, in which case the lining swells in response to a viral infection.
Doctors often refer to swelling of the lining of the nose as “rhinitis” and it can have many other causes. Apart from viral infections, rhinitis may be due to bacterial infection in the nose and sinuses, allergy, or overuse of nasal decongestant medication. Occasionally the mucous membrane swells enough to cause the formation of polyps in the nose. For more information on nasal polyps please see the appropriate patient information leaflet.