What Is Chronic Sinusitis?

Prolonged Sinus Infection

Man with sinus pain
Man with sinus pain. Stockbyte/Getty Images

Chronic sinusitis is sinus infection that lasts longer than 12 weeks. Sinusitis occurs when the sinuses become blocked and are unable to drain the mucous they continually produce. Stagnant secretions and lack of oxygen create an environment for microorganisms to grow. In the case of acute sinusitis, (sinusitis that lasts a month or less), the blockage is usually caused by excess or thick mucous combined with inflammation.

In the case of chronic sinusitis there may be underlying conditions which contribute to the development of sinusitis and make it more difficult to treat. While acute sinusitis can often be treated with a course of antibiotics, chronic sinusitis may require several rounds of antibiotics or even surgery to cure.

Most research agrees that there may be several underlying factors that contribute to the development of chronic sinusitis. We will talk about known conditions which cause or contribute to chronic sinusitis below.

From Structural Abnormalities

Structural abnormalities such as enlarged or diseased tissue which blocks the sinuses from draining can lead to chronic sinusitis and often requires surgery to treat. Examples are:

Nasal polyps are masses of benign tissue that grow inside of the sinuses and nasal passageways.

It is unclear why some individuals are prone to develop nasal polyps but for some it can lead to repeated bouts of chronic sinusitis and multiple procedures to have polyps removed. Ironically having chronic sinusitis in and of itself can lead to diseased tissue or abnormal growths like nasal polyps.

Some birth defects can also increase the risk of conditions like a deviated septum or affect the anatomy of the face, increasing the risk of sinusitis.

From Immunodeficiency

If you have a weakened immune system, you may be at risk for suffering from chronic sinusitis. Repeated infections, such as the common cold lead to inflammation and excess mucous, resulting in a blockage of the sinuses. Once the infection has taken root,  you will have a more difficult time recovering from the sinus infection. If you have a weakened immune system, you will also be more likely to have chronic sinus infections caused by a fungus.

From Exposure to Toxins

Inhaled environmental toxins can contribute to chronic sinusitis. Probably the most common environmental toxin associated with chronic sinusitis is tobacco smoke. However, a person may be exposed to chemicals or other toxins through their occupation which may predispose them to the development of chronic sinusitis.

From Allergies

Any allergy that causes inflammation or congestion can predispose a person to the development of sinusitis. However, allergies to fungus are specifically associated with the development of chronic sinusitis because fungal allergies cause the mucous to become abnormally thick.

Fungal allergies are also more common in someone who has a weakened immune system but may occur in people with healthy immune systems as well.

Conditions That Can Increase Your Risk

The following conditions are also known or suspected to be associated with the development of chronic sinusitis.

Treatment and Prevention

Chronic sinusitis tends to recur in people who are prone to it, so management of symptoms and treatment of underlying disorders is necessary for most people to prevent recurring sinusitis.

Long term management may include:

Using a neti pot may help to prevent sinusitis according to some studies. However, at least one study has shown that the opposite may be true and daily nasal irrigation may actually increase your risk of sinusitis.


Medscape. Allergic Fungal Sinusitis. Accessed: January 30, 2013 from http://emedicine.medscape.com/article/834401-overview

Medscape. Chronic Sinusitis. Accessed: January 30, 2013 from http://emedicine.medscape.com/article/232791-overview#aw2aab6b2b4aa

Pubmed. Chronic sinusitis: risk factors for extensive disease. Accessed: January 30, 2013 from http://www.ncbi.nlm.nih.gov/pubmed/9275139

Uptodate. Chronic rhinosinusitis. Accessed: January 30, 2012 from http://www.uptodate.com/contents/chronic-rhinosinusitis-beyond-the-basics