What are the types of sinusitis?

Sinusitis may be classified in at several ways, based on the time span of the problem (acute, subacute, or chronic) and the type of inflammation (either infectious or noninfectious).

• Acute sinus infection (also termed acute sinusitis caused by infection) is usually defined as being of less than 30 days duration.
• Subacute sinus infection as being over 1 month but less than 3 months.
• Chronic sinus infection as being greater than 3 months duration.

There is no medical consensus on the above time periods.

• Infected sinusitis usually is caused by uncomplicated virus infection. Less frequently, bacterial growth causes sinus infection and fungal sinus infection is very infrequent. Subacute and chronic forms of sinus infection usually are the result of incomplete treatment of an acute sinus infection.
• Noninfectious sinusitis is caused by irritants and allergic conditions and follows the same general time line for acute, subacute and chronic as infectious sinusitis.

http://www.medicinenet.com/sinusitis/page2.htm

What causes sinus infections?

Sinus infection may be initiated caused by anything that interferes with airflow into the sinuses and the drainage of mucus out of the sinuses. The sinus openings (ostea) may be blocked by swelling of the tissue lining and adjacent nasal passage tissue, for example with common colds, allergies, and tissue irritants such as OTC nasal sprays, cocaine, and cigarette smoke. Sinuses can also become blocked by tumors or growths that are near the sinus openings.
The drainage of mucous from the sinuses can also be impaired by thickening of the mucous secretions, by decrease in hydration (water content) of the mucous brought on by disease (cystic fibrosis), drying medications (antihistamines), and lack of sufficient humidity in the air. The epithelial cells have small hairlike fibers, called cilia, which move back and forth to help the mucus move out of the sinuses. These small cilia may be damaged by many irritants, especially smoke. This can prevent them from assisting the mucus in draining from the sinuses.
Stagnated mucus provides an environment for bacteria, viruses and in some circumstances (for example, AIDS or immunodepressed persons) fungus to grow within the sinus cavities. In addition, the microbes themselves can initiate and exacerbate sinus blockage. The most commonly infected sinuses are the maxillary and ethmoid sinuses.

http://www.medicinenet.com/sinusitis/page2.htm

What is a sinus infection?

 

What is a sinus?

Sinus infection is the infection of the paranasal sinus. This leads to the inflammation of the sinuses, a condition commonly known as Sinusitis. The human skull houses four pairs of paranasal sinuses. These are located in the forehead (Frontal sinuses), at the back of the cheek bones (Maxillary sinuses), between the eyes (Ethmoid sinuses) and at the rear of the eyes (Sphenoid sinuses). Identifying these types of paranasal sinuses is very important as sinus infection symptoms, though some are present in all four, can have notable differences depending on the location of the infection.