Skip to content

    Allergies Health Center

    Font Size
    A
    A
    A

    Sinusitis - Cause

    Sinusitis is most often the result of a viral infectionthat causes the mucous membranelining the inside of the nose and the sinuses to become inflamed.

    • The mucous membrane swells when it becomes inflamed, blocking the drainage of fluid from the sinuses into the nose and throat.
    • Mucus and fluid build up inside the sinuses, causing pressure and pain.
    • Bacteria are more likely to grow in sinuses that are unable to drain properly. Bacterial infectionin the sinuses often causes more inflammation and pain.

    Colds usually trigger this process, but any factor that causes the mucous membrane to become inflamed may lead to sinusitis. Many people with nasal allergies (allergic rhinitis), for instance, are likely to have recurring or long-term (chronic) sinus infections. Nasal polyps, foreign objects (usually in children), structural problems in the nose such as a deviated septum, and other conditions can also block the nasal passages, increasing the risk of sinusitis.

    Recommended Related to Allergies

    Indoor Fun for Allergic Kids

    For the thousands of children with seasonal allergies, rising pollen counts mean nasal congestion, itchy eyes, irritated throat, and feeling tired. A good way to cope is to keep your kids away from allergy triggers like tree, grass, and weed pollen. When the pollen count is high, keep allergic children indoors. But what do you do with bored, cranky kids? To help, WebMD gathered tips from the experts -- parents and allergy doctors -- to help you keep tots and tweens entertained when the pollen...

    Read the Indoor Fun for Allergic Kids article > >

    Fungal infectionsmay also cause sinusitis. This is especially true in people with impaired immune systems. Fungal sinusitis tends to be chronic and harder to treat than bacterial sinusitis.

    WebMD Medical Reference from Healthwise

    Last Updated: November 14, 2014
    This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.
    1
    Next Article:

    Today on WebMD

    man blowing nose
    Make these tweaks to your diet, home, and lifestyle.
    Allergy capsule
    Breathe easier with these products.
     
    cat on couch
    Live in harmony with your cat or dog.
    Woman sneezing with tissue in meadow
    Which ones affect you?
     

    blowing nose
    Article
    woman with sore throat
    Article
     
    lone star tick
    Slideshow
    Woman blowing nose
    Slideshow
     

    Send yourself a link to download the app.

    Loading ...

    Please wait...

    This feature is temporarily unavailable. Please try again later.

    Thanks!

    Now check your email account on your mobile phone to download your new app.

    cat lying on shelf
    Article
    Allergy prick test
    VIDEO
     
    Man sneezing into tissue
    Assessment
    Woman holding feather duster up to face, twitching
    Quiz