Are sinus infections contagious?

When our work colleagues or family members come down with sinus symptoms, one of the first things that crosses our minds is often “I hope I don’t catch that!” So we often try to steer clear—we don’t want to wind up coughing, sneezing, wheezing, or having headaches. But sinus infections aren’t always contagious—the thing is, it can be difficult or impossible to know just by looking at someone.

Different causes, different answers

The answer to the question “are sinus infections contagious?” depends on what’s causing the infection.[1] There are several different causes of sinus infections, and some of these can be transmitted. Here are some of the main causes of sinus infections:

  • Viruses. Most sinus infections are caused by viruses, which are organic things tinier than bacteria (more below). They are “genetic entities that lie somewhere in the grey area between living and non-living states,” as a University of California website puts it.[2]
    Viruses are passed from one person to another, so if someone has a viral sinus infection, they can pass the bug to you. However, you may not develop the same symptoms. The common cold is caused by viruses, and these viruses can cause a sinus infection to develop. Viruses can be contagious for as little as a few days or as long as a week or more, and you can pass a virus even before you’re showing any symptoms of being sick.
  • Bacteria. Bacterial infections can grow when the sinuses are blocked and full of mucus. These infections often last longer. Bacterial sinus infections can’t be spread from person to person. While there is no simple test that will easily and quickly determine whether a sinus infection is viral or bacterial, the Infectious Diseases Society of America (IDSA) has noted that a sinus infection is likely caused by bacteria if:[3]
    • symptoms last for 10 days or more and are not improving; or
    • symptoms are severe, including fever of 102° or higher, nasal discharge and facial pain lasting 3-4 days in a row; or
    • symptoms get worse, with new fever, headache or increased nasal discharge, typically after a viral upper respiratory infection that lasted five or six days and initially seemed to improve.
  • Environment, allergies, other reasons. If a person has a deviated septum (when the wall separating the nostrils is crooked) or nasal polyps (growths inside the nostrils), experiences allergic reactions, or breathes dry, polluted, or smoky air, they may get sinus infections as a result. These things can’t be passed on, but if something in the sufferer’s environment is causing symptoms, they should think about evaluating their environment and making positive changes.

If you are experiencing symptoms of a sinus infection it is best to visit a healthcare professional to distinguish your symptoms between a viral and bacterial sinus infection. An ear, nose and throat (ENT) doctor is specially trained and has passed a certification examination for the American Board of Otolaryngology, making them experts in treating the sinuses. Find an ENT doctor using this physician locator.

How do I avoid catching (or giving) an infection?

It’s important to practice good hygiene as an everyday preventative measure. Wash your hands regularly and thoroughly, and don’t touch your face; steer clear of people who are coughing, sneezing, and stuffed up. If you have a sinus infection, wash your hands often, and cover your mouth and nose when you cough or sneeze.