30 September 1999

Don’t Blow…..

by Kate Melville

Blowing your nose can propel mucus into the sinuses potentially increasing the severity of a cold and risk of bacterial infection. If this new finding is correct it may have major implications for the treatment of common colds as the severity of a cold can be increased if mucus accumulates in the sinuses especially if there is a secondary bacterial infection of the sinus.

This new finding come from a collaborative study done at the University of Aarhus in Denmark and University of Virginia in the USA.

In the research nose blowing by adult volunteers produced pressure in the nose similar to diastolic blood pressure. Such pressure is capable of propelling nasal mucus into the sinuses and this was confirmed by CT scan. Following nose blowing the CT scan showed deposits in the sinuses whereas sneezing and coughing (which produce a much lower pressure) showed no similar deposits in the sinuses.

Basically this means there is a potential risk for each nose blow to introduce nasal secretions into the sinuses. During colds, nasal secretions contain virus and bacteria, as well as inflammatory mediators.

The study provides new information on the mechanisms by which sinusitis occurs and has implications for treatment of colds. Treatments that reduce nasal fluid production are desirable not only because of their symptomatic benefits but also because of the possibility that they may help prevent spread of the cold to the sinuses. However any treatment must be started early in the cold to achieve any real benefit.