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Alternative names

Acute sinusitis; Sinus infection; Sinusitis - acute


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

The sinuses are air-filled spaces around 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 to 8 weeks) or chronic, with symptoms lingering much longer.

See also chronic sinusitis .

Causes, incidence, and risk factors

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 the normally produced mucous out, are not working properly
  • Too much mucous is produced

When the sinus openings become blocked and mucous 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 or a weakened immune system (such as people with HIV and those receiving chemotherapy).

Other risks for developing sinusitis include:

  • Having asthma
  • Overuse of nasal decongestants (rather than continuing to relieve congestion, the problem gets worse when these are used too often or for too long)
  • Having a deviated nasal septum, nasal bone spur, or polyp
  • Presence of a foreign body in your nose
  • Frequent swimming or diving
  • Dental work
  • Pregnancy
  • Changes in altitude (flying or climbing)
  • Air pollution and smoke
  • Gastroesophageal reflux disease (GERD)

Hospitalization, especially if the reason you are in the hospital is related to a head injury or you needed a tube inserted into the nose (for example, a nasogastric tube from your nose to your stomach)

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's 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 to 7 days of symptoms. They include:

Signs and tests

Your doctor will test for sinusitis by:

  • Tapping over a sinus area. Tenderness may indicate infection.
  • Shining a light against the sinus (called transillumination). If dark, this indicates possible inflammation.

Other tests that might be considered include:

  • Viewing the sinuses through a fiberoptic scope
  • Ultrasound
  • 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:

Expectations (prognosis)

Sinus infections are usually curable with self-care measures and medical treatment. If you are having recurrent attacks, you should be evaluated for underlying causes (such as nasal polyps or another structural problem).


Although very rare, complications that may arise include:

  • Osteomyelitis -- infection that spreads to the bones in the face
  • Meningitis -- infection that spreads to the brain
  • Orbital cellulitis -- infection that spreads to the area surrounding the eye
  • Abscess
  • Blood clot
  • The bacteria causing your sinusitis may develop resistance to antibiotics commonly used to treat the infection; this makes it more difficult to find the best treatment for your sinus infection

Calling your health care provider

Call your doctor if:

  • Your symptoms last longer than 10 to 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:

Update Date: 10/28/2003

Jacqueline A. Hart, M.D., Department of Internal Medicine, Newton-Wellesley Hospital, Boston, Ma., and Senior Medical Editor, A.D.A.M., Inc. Previously reviewed by Ashutosh Kacker, M.D., Department of Otolaryngology, New York Presbyterian Hospital, New York, NY. Review provided by VeriMed Healthcare Network (1/23/2002).

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Last updated: Tue, 06 Jan 2009 00:20:03 GMT