Medical Mythbusters - Green Snot!
Posted: March 1, 2010
True or False: My snot is green so I need an antibiotic, right?
This is one of the most tenacious, and frustrating, medical myths out there: that clear snot indicates a viral infection that will clear on its own while green snot automatically means a bacterial infection that requires an antibiotic for treatment.
This is simply not true! Coming down with a sinus infection is very common this time of year. You may know the symptoms: headache, stuffy nose, nasal discharge, facial pain and pressure, fever, cough and ear pressure. The vast majority of cases are caused by viruses and resolve on their own within 10 days. The only time antibiotics are recommended is when the infection lasts for more than 10 days, or worsens over 5-7 days.
Many people come to the doctor expecting antibiotics for minor viral infections but keep in mind that not only do antibiotics do nothing against viruses, they are not always benign either. They can have side effects such as upset stomach and diarrhea. More importantly, overuse can lead to resistance, so that if heaven forbid you come down with a serious infection that does require antibiotics in the future, they may not work as well and the infection will be more difficult to treat.
As for the myth of the green snot, microbiologists believe the color comes from enzymes released by your white blood cells (myelo-peroxidases and other oxidases) to break down bacteria and other organisms. These enzymes contain iron, which gives off a greenish color. Also, the longer the mucus stagnates in your sinuses, the more likely it is to look green when it comes out. So when your sinuses are clogged up during a sinus infection, it is more likely to stagnate and appear green, just as your early morning snot will be more green just from sitting in your nose all night. The only kind of snot that deserves antibiotics is purulent (think pus) mucus coming from your nose or throat.
Remember, most of these infections clear on their own with a little TLC. Over the counter products such as pseudoephedrine ("Sudafed") or my personal favorite, the neti pot are usually effective at alleviating the symptoms while the infection runs its course.
If your sinus infection has been going on for more than 10 days, or it's been getting worse over the past week, be sure to contact Student Health Services to be evaluated.
Angela Walker, Med IV (OSU COM)
John A. Vaughn, MD (OSU SHS)