What is Asthma?

Asthma is a very complex disease that is known for its different and recurring symptoms such as coughing and wheezing, airflow obstruction, and very responsive and swollen airways. According to the EPR-3 Guidelines for the Diagnosis and Management of Asthma (2007) , the working definition of asthma is as follows:

Asthma is a chronic inflammatory disorder of the airways in which many cells and cellular elements play a role: in particular , mast cells, eosinophils, neutrophils (especially in sudden onset, fatal exacerbations, occupational asthma, and patients who smoke), T lymphocytes, macrophages, and epithelial cells.

In susceptible individuals, this inflammation causes recurrent episodes of coughing (particularly at night or early in the morning), wheezing, breathlessness, and chest tightness. These episodes are usually associated with widespread but variable airflow obstruction that is often reversible either spontaneously or with treatment.

If Asthma is not properly treated, then airway remodeling may occur. Airway remodeling is the incomplete reversibility after an asthma episode in some patients. View more information about airway remodeling.

Causes of Asthma

According to recent and ongoing research, the development of asthma seems to involve numerous factors that can impact the course of the disease. These factors include:

  • Immunity : Certain studies suggest that children who are exposed to other children, enrolled in childcare, and lived in the country have a lower-incidence of asthma. This is called the "hygiene hypothesis".

  • Genetics : Asthma is inheritable, but more study is needed.

  • Environmental Factors: Allergens, respiratory infections and colds, tobacco smoke, air pollution, and diet may play a part in asthma development, but study is still ongoing.

View more information about the new EPR-3 Guidelines.