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A chronic inflammatory disorder of the airways. Airway inflammation is associated with airway hyper-responsiveness, airflow limitation, and respiratory symptoms. In susceptible individuals this inflammation causes recurrent episodes of wheezing, breathlessness, chest tightness, and cough, particularly at night and/or in the early morning. These symptoms are usually associated with widespread but variable airflow limitation. Asthma also causes an associated increase in airway responsiveness to a variety of stimuli.

Asthma management

A comprehensive approach to achieving and maintaining control of asthma. It includes patient education to develop a partnership in management, assessing and monitoring severity, avoiding or controlling asthma triggers, establishing plans for medication and management of exacerbations, and regular follow-up care.


The propensity, usually genetic, for developing IgE-mediated responses to common environmental allergens.

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Causal factors

Risk factors that sensitize the airways and cause the onset of asthma. The most important of these factors are allergens and chemical sensitizes.

Contributing factors

Risk factors that either augment the likelihood of asthma developing upon exposure to them, or may even increase susceptibility to asthma. These factors including smoking, viral infections, small size at birth, and environmental pollutants.

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Environmental control

Removal of risk factors from the environment.


Any worsening of asthma. Onset can be acute and sudden, or gradual over several days. A correlation between symptoms and peak flow is not necessarily found.

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PEF (peak expiratory flow) home monitoring

Measurement of PEF on regular basis at home with a portable peak flow meter. PEF home monitoring is especially useful to patients over 5 years of age with moderate persistent to severe persistent asthma.

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Risk factor

An agent that when present increases the probability of disorder expression. There are two types of risk factors:

  • Risk factors involved in the development of the condition of asthma can be inherited, such as atopy. Alternatively, a risk factor can be due to environmental exposure. See “causal factors” and “contributing factors.”
  • Risk factors that cause asthma exacerbation in individuals who already have the condition. These are also called triggers.

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A risk factor that causes exacerbation of asthma; a stimulus that causes an increase in asthma symptoms and/or airflow limitation.

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Page last reviewed: September 21, 2009