Asthma is a chronic illness characterized by symptoms such as shortness of breath, wheezing and cough, which vary in intensity over time. The primary pathogenic process driving the manifestations of asthma is airway inflammation which leads to two pathophysiological features of asthma: hyper-responsiveness or twitchiness of the airways in response to stimuli such as exercise or allergen exposure, and airway obstruction.5
Airway obstruction in asthma is due to three main factors:
1. Bronchoconstriction, where the smooth muscle surrounding the airways tightens in response to a trigger (e.g. exercise) and narrows the airway
2. Swelling of the airway wall due to inflammation
3. Mucus formation within the airways that obstructs the airflow
Narrower airways obstruct the normal flow of air, making it difficult to breathe and leading to typical signs and symptoms of asthma (like wheezing, coughing, chest tightness and shortness of breath). Worsening symptoms can result in an episode of “asthma attack,” or exacerbation.
Source: http://www.apieron.com/
