Sinusitis

Sinusitis (sy-nyoo-SY-tis) is an inflammation of the sinuses (SY-nuh-ses), the hollow chambers or cavities located in the bones of the face that surround the nose.

What Causes Sinusitis?

People have four pairs of paranasal sinuses (the sinuses surrounding the nose):

* Frontal sinuses, located in the forehead and over the eyebrows

* Ethmoid (ETH-moyd) sinuses, located between the eyes at the bridge of the nose

* Sphenoid (SFEE-noyd) sinuses, located behind the ethmoid sinuses

* Maxillary (MAX-ih-lary) sinuses, located in the cheekbones

The sinuses and the narrow tube-like structures that link them to the nasal passages are lined with the same mucous membranes that line the nose. Colds, allergies, and exposure to some chemicals can cause swelling and inflammation in the lining of the sinus passages and block sinus drainage. Bacteria (such as Streptococcus pneumoniae, strep-tuh-KAH-kus nu-MO-nye), viruses, and fungi that live in the body may become trapped, multiply, and invade the inflamed sinuses.

People with allergies, asthma, and cystic fibrosis are more likely to have sinus infections. Other candidates for sinusitis are people with a weakened immune system, such as those who have AIDS or cancer; people with narrow sinus passages or with growths or blockages in the nasal area, such as tumors or polyps; and people with previously broken or deformed nasal bones. The risk of sinusitis also is higher when people swim or dive, due to the pressure this activity puts on the sinus cavities.

What Are Different Types of Sinusitis?

Physicians classify sinusitis in three ways:

* Acute sinusitis often develops after a person has had a cold, with symptoms lasting less than three weeks.

* Chronic sinusitis can last three to eight weeks or longer. It often occurs in people who have allergies or asthma

* Recurrent sinusitis consists of several acute episodes of sinusitis in one year.

How Common Is Sinusitis?

The National Institute of Allergy and Infectious Diseases estimates that every year 37 million people in the United States have sinusitis.

Is Sinusitis Contagious?

No one can catch a sinus infection from another person, but the viruses and bacteria that cause colds and other respiratory tract* infections that can trigger sinusitis may spread from person to person in drops of fluid from the nose or mouth. When people who have sinusitis cough, sneeze, laugh, or talk, they can transmit germs to their hands, to the surfaces around them, and into the air. Others can then breathe in the germs or touch contaminated surfaceswith their hands and spread the germs to their noses and mouths. Such infections sometimes develop into sinusitis.