Uh-oh. You're sneezing, coughing, and you have a bright red nose. You figure it's just another cold, but this one sticks around way too long. Is it really a cold? Maybe not. It could be a problem with your sinuses.

What Are Sinuses?

The sinuses (say: sy-nus-is) are air-filled spaces found in the bones of the head and face. Sinuses start developing before you are born and some of them keep growing until you're about 20. There are four pairs of sinuses, or eight in all. They are located on either side of the nose in your cheeks, behind and between the eyes, in the forehead, and at the back of the nasal cavity.

Like the inside of the nose, the sinuses are lined with a moist, thin layer of tissue called a mucous membrane (say: myoo-kus mem-brayne). The mucous membranes help moisten the air as you breathe it in. The mucous membrane also makes mucus, that sticky stuff in your nose you might call snot. The mucus traps dust and germs that are in the air we breathe. On the surface of the cells of the mucous membrane are microscopic hairs called cilia (say: sih-lee-uh).

The cilia beat back and forth in waves to clear mucus from the sinuses through a narrow opening in the nose and then move the mucus toward the back of the nose to be swallowed. Gross, huh? If you have a cold or allergies, the membrane gets irritated and swollen and produces even more mucus.

What Do Sinuses Do?

No one is completely sure why we have sinuses, but some researchers think they keep the head from being too heavy. Sinuses are pockets of air, and air doesn't weigh very much. If those pockets were solid bone, your head would weigh more.

Sinuses also give you the depth or tone of your voice. Did you ever notice how funny your voice sounds if your nose and sinuses get stuffy when you have a cold?

When Good Sinuses Go Bad

What about that cold that won't go away? A cold virus can:

• damage the delicate cilia so that mucus is not swept away
• cause the mucous lining of the nose to become swollen, which narrows and blocks the small opening from the sinuses into the nose
• lead to the production of more mucus, which is often thicker and stickier, making it harder to flow out of the sinuses

When the tiny openings that drain the sinuses get blocked, mucus becomes trapped in the sinuses. Like water in a stagnant pond, it makes a good home for bacteria, viruses, or fungi to grow.

If a cold lasts for more than 10 to 14 days (sometimes you may have a low-grade fever), you may have sinusitis (say: syne-yuh-sy-tus). This means an infection of the sinuses. Sinusitis is a pretty common infection; in fact, close to 37 million people in the United States have sinusitis each year.

Acute Sinusitis Lasts A While

Acute sinusitis may be diagnosed when a cold lasts more than 10 to 14 days. Chronic sinusitis means a person has had symptoms for more than 3 months. Symptoms may be similar to acute sinusitis, but typically are less severe and not associated with fever.

In either case, symptoms may include:

• fever
• persistent nasal discharge that often is yellow or green (this alone doesn't always mean you have a sinus infection)
• daytime cough (your cough may be worse at night)
• puffy eyes, especially in the morning
• bad breath

Less often, a kid could have headache or pain behind the eyes, forehead, and cheeks.

What Will the Doctor Do?

If a doctor thinks you have a sinus infection, he or she will probably examine your ears and throat and take a look in your nose. The doctor may also check your sinuses by tapping or pressing on your forehead and cheeks. If you have a sinus infection, the doctor may prescribe an antibiotic. If bacteria are causing the problem, an antibiotic will help by killing the bacteria. If it's a virus, antibiotic medicine won't work.

In the case of a bacterial infection, the antibiotic should help you feel better in a few days. A decongestant or nasal spray might also be prescribed to help you feel better. If the sinus infection is chronic, the doctor may have you take medicine for a couple of weeks, just to be sure all the bacteria are knocked out.

Sometimes, if a sinus infection is not getting better, comes back even after you take all your medicine, or if the doctor is thinking about doing surgery, he or she might send you to have a CT scan of the sinuses. The CT scan is a special X-ray that takes a picture of your insides. It doesn't hurt, and it makes it much easier for the doctor to see what's going on. Your doctor can clearly see what the sinuses look like and then decide what kind of treatment will help you get better faster.

The good news about sinusitis is that it's not contagious, so if you are feeling well enough, you can go to school or go outside and play. In no time, you'll be over your infection — and you'll be saying so long to sinusitis!

Reviewed by: Steven Dowshen, MD
Date reviewed: September 2010