Sinus Infection

Sinus Infection



A sinus is a hollow, air-filled cavity. For the purposes of this article, a sinus will referred to those hollow cavities that are in the skull and connected to the nasal airway by a narrow hole in the bone (ostium). Normally all are open to the nasal airway through an ostium. Humans have four pair of these cavities each referred to as the:

1. frontal sinus (in forehead),
2. maxillary sinus (behind cheeks),
3. ethmoid sinus (between the eyes), and
4. sphenoid sinus (deep behind the ethmoids).

The four pair of sinuses are often described as a unit and termed the "paranasal sinuses." The cells of the inner lining of each sinus are mucus-secreting cells, epithelial cells and some cells that are part of the immune system (macrophages, lymphocytes, and eosinophils).

Functions of the sinuses include humidifying and warming inspired air, insulation of surrounding structures (eyes, nerves), increasing voice resonance, and as buffers against facial trauma. The sinuses decrease the weight of the skull.


What is a sinus infection?

A sinus infection occurs when a pathogenic organism (virus, bacterium, or a fungus) grows within a sinus and causes intermittent blockage of the sinus ostium. Drainage of mucus and pus often occur when the blockage is relieved. The drainage usually goes from the nasal passages to the throat or out the nostrils. Such infections also cause inflammation (an influx of immune cells and swelling of the sinus tissue) of one or more sinuses. This adds to blocking the openings of the sinuses and causes discomfort.

Inflammation of the air cavities within the passages of the nose (paranasal sinuses) is referred to as sinusitis. Sinusitis can be caused by infection, but can also be caused by allergy and irritation of the sinuses.

Sinusitis is one of the more common conditions that can afflict people throughout their lives. Sinusitis commonly occurs when environmental pollens irritate the nasal passages, such as with hay fever. Sinusitis can also result from irritants, such as chemicals or the use and/or abuse of over-the-counter (OTC) nasal sprays, and illegal substances that may be snorted through the nose. About 30 million adults have "sinusitis."

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Sinus Infection - Effective Treatments
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Sinus Infection

Exercise-Induced Asthma »
What Is Exercise-Induced Asthma?

Like it sounds, exercise-induced asthma is asthma that is triggered by vigorous or prolonged exercise or physical exertion. Most people with chronic asthma experience symptoms of asthma during exercise. However, there are many people without chronic asthma who develop symptoms only during exercise.

Why Does Exercise Induce Asthma?

During normal breathing, the air we take in is first warmed and moistened by the nasal passages. Because people tend to breathe through their mouths when they exercise, they are inhaling colder and drier air.

In exercise-induced asthma, the muscle bands around the airways are sensitive to these changes in temperature and humidity and react by contracting, which narrows the airway. This results in symptoms of exercised-induced asthma, which include:

* Coughing with asthma
* Tightening of the chest
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