Sinusitis refers to inflammation of the sinuses. This is generally caused by a viral, bacterial, or fungal infection.

The sinuses are air-filled spaces in the skull (behind the forehead, cheeks, and eyes) that are lined with mucous membranes. Healthy sinuses are sterile (meaning that they contain no bacteria or other organisms) and open, allowing mucus to drain and air to circulate.

When inflamed, the sinuses become blocked with mucus and can become infected. Each year, over 30 million adults and children get sinusitis.

Sinusitis can be acute (lasting anywhere from 2 - 8 weeks) or chronic, with symptoms lingering much longer.

See also: Chronic sinusitis

Sinusitis can occur from one of these conditions:

• The small openings (ostia) from the sinuses to the nose become blocked.
• Small hairs (cilia) in the sinuses, which help move mucus out, are not working properly.
• Too much mucus is produced.

When the sinus openings become blocked and mucus accumulates, this becomes a great breeding ground for bacteria and other organisms.

Sinusitis usually follows respiratory infections, such as colds, or an allergic reaction. Some people never get sinusitis, and others develop sinusitis frequently.

People more likely to get frequent sinusitis include those with cystic fibrosis and those with immune systems weakened by HIV or chemotherapy.

The following may increase your risk for developing sinusitis:

• Air pollution and smoke
• Asthma
• Changes in altitude (flying or scuba diving)
• Dental work
• Deviated nasal septum, nasal bone spur, or polyp
• Foreign body in your nose
• Frequent swimming or diving
• Gastroesophageal reflux disease (GERD)
• Hospitalization, especially if you are in the hospital because of a head injury or have had a tube placed into your nose (nasogastric tube)
• Overuse of nasal decongestants (rather than continuing to relieve congestion, the problem gets worse when these are used too often or for too long)
• Pregnancy

Cystic fibrosis is one of a number of diseases that prevent the cilia from working properly. Other such diseases that put you at increased risk for sinusitis include Kartagener syndrome and immotile cilia syndrome.

The classic symptoms of acute sinusitis usually follow a cold that does not improve, or one that worsens after 5 - 7 days of symptoms. They include:

• Nasal congestion and discharge
• Sore throat and postnasal drip (fluid dripping down the back of your throat, especially at night or when you lie down)
• Headache -- pressure-like pain, pain behind the eyes, toothache, or facial tenderness
• Cough, often worse at night
• Fever (may be present)
• Bad breath or loss of smell
• Fatigue and generally not feeling well

Symptoms of chronic sinusitis are the same as acute sinusitis, but tend to be milder and last longer than 8 weeks.

Your doctor will test for sinusitis by:

• Tapping over a sinus area; tenderness may indicate infection.
• Shining a light against the sinus (transillumination); if dark, this indicates possible inflammation.

Other tests that might be considered include:

• Viewing the sinuses through a fiberoptic scope
• X-ray of the sinuses
• Cultures of the material from the nose

However, these tests are relatively insensitive for detecting sinusitis, and are often considered unnecessary.

A CT scan of the sinuses is a much better test to help diagnose sinusitis. If sinusitis is thought to involve tumor or fungal infections, an MRI of the sinuses may be necessary.

If you have chronic or recurrent sinusitis, further laboratory evaluation may be necessary to look for an underlying disorder. This may involve sweat chloride tests for cystic fibrosis, ciliary function tests, blood tests for HIV or other tests for immunodeficiency, allergy testing, or nasal cytology (checking the cells in the nasal secretions).

Try the following measures to help reduce congestion in your sinuses:

• Use a humidifier.
• Spray with nasal saline several times per day.
• Inhale steam 2 - 4 times per day (for example, sitting in the bathroom with the shower running).
• Drink plenty of fluids to thin the mucus.
• Apply a warm, moist washcloth to your face several times a day.

Be careful with over-the-counter spray nasal decongestants. They may help at first, but using them beyond 3 - 5 days can actually worsen nasal congestion.

Also, for sinus pain or pressure:

• Avoid temperature extremes, sudden changes in temperature, and bending forward with your head down.
• Try acetaminophen or ibuprofen.
• Avoid flying when you are congested.

If self-care measures are not working, your doctor will consider prescription medications, antibiotics, further testing, or referral to an ear, nose, and throat (ENT) specialist.

Nasal corticosteroid sprays may be used to decrease swelling, especially if you have swollen structures (such as nasal polyps) or allergies.

Antibiotics are used to cure the particular infection causing sinus inflammation.

Other antibiotics may be used depending on the type of organism present. Acute sinusitis should be treated for 10 - 14 days, while chronic sinusitis should be treated for 3 - 4 weeks.

Surgery to clean and drain the sinuses may also be necessary, especially in patients with recurrent episodes of inflammation despite medical treatment. An ENT specialist, also known as an otolaryngologist, can perform this surgery.

Most fungal sinus infections require surgery. Finally, surgical repair of a deviated septum or nasal polyps may prevent recurrence.

Sinus infections are usually curable with self-care measures and medical treatment. If you are having recurrent attacks, you should be checked for underlying causes such as nasal polyps or other problems.

Although very rare, complications may include:

• Abscess
• Antibiotic resistance, a situation in which the bacteria causing your sinusitis no longer responds to medicines used to treat the infection
• Meningitis, an infection that spreads to the brain
• Orbital cellulitis, an infection that spreads to the area surrounding the eye
• Osteomyelitis, an infection that spreads to the bones in the face

Call your doctor if:

• Your symptoms last longer than 10 - 14 days or you have a cold that gets worse after 7 days
• You have a severe headache, unrelieved by over-the-counter pain medicine
• You have a fever
• You still have symptoms after taking all of your antibiotics properly

A green or yellow discharge does not necessarily indicate a sinus infection or the need for antibiotics.

The best way to prevent sinusitis is to avoid or quickly treat flus and colds:

• Get an influenza vaccine each year.
• Wash your hands frequently, particularly after shaking hands with others.
• Eat plenty of fruits and vegetables, which are rich in antioxidants and other chemicals that could boost your immune system and help your body resist infection.
• Reduce stress.

Additional tips for preventing sinusitis:

• Avoid smoke and pollutants.
• Use a humidifier to increase moisture in your nose and sinuses.
• Drink plenty of fluids to increase moisture within your body.
• Take decongestants during an upper respiratory infection.
• Treat allergies promptly and appropriately.

Cincinnati Children's Hospital Medical Center. Evidence-based care guideline for management of acute bacterial sinusitis in children 1-18 years of age. Cincinnati (OH): Cincinnati Children's Hospital Medical Center; 2006 Jul 7. 17 p.

Slavin RG. The diagnosis and management of sinusitis. J Allergy Clin Immunol. Dec 2005; 116(6 Suppl): S13-47.