The Nasal Discharge Color Myth

A great many rumors tend to circulate about sinus infections and the common cold at any one time, many of which center around how to diagnose an infection on sight.  One of the most common ideas is that nasal discharge color is somehow diagnostic; that is, you can tell whether you have an infection just by looking at the color of your mucus.  Darker shades indicate degrees of infection, goes the myth, and green mucus should always be treated immediately with antibiotics.  We physicians aren’t immune to such ideas either – a great many doctors continue to subscribe (and prescribe!) to this common misconception.

But it’s wrong.  The truth is that the color of your nasal discharge is dictated by any number of factors, from its age to the humidity in your room.  Nasal discharge can actually grow lighter during an infection and darker after it has vanished.  And even in cases when a darker shade does suggest an infection, it tells you nothing about the quality of your infection – it could be viral, or it could be bacterial.  Only one responds to antibiotics, so it’s important to get it right before anyone makes a trip to the drugstore:

In a definitive study from 1984, scientists put 142 children with green nasal discharge into groups, including one that was treated with antibiotics and another that received a placebo. They found that the drugs had no effect on “potentially pathogenic organisms” or on symptoms. About 35 percent of subjects treated with antibiotics showed improvement, compared with 31 percent in the placebo group. The 4 percent difference was not statistically significant.  More recent studies have bolstered that conclusion.

Sinus infections do not always follow from common colds, so it is important to speak with a sinus expert before beginning a round of potentially unnecessary antibiotics.  Viral infections and bacterial infections require different courses of treatment.  Understanding the difference between the two is essential to maintaining good health during cold and flu season.  So listen to your body, contact an experienced sinus specialist if you have any questions, and remember: your sinuses are color-blind.