Asthma symptoms occur when the airways of the lungs narrow, which makes it more difficult to breathe. This narrowing is usually caused by inflammation, which makes the airways swell and may cause the cells of the airway to make excess mucus.
To understand asthma, it helps to know how the airways work. The airways are tubes that carry air into and out of your lungs. People who have asthma have inflamed airways. The inflammation makes the airways swollen and very sensitive.
Pathophysiology and Pathogenesis of Asthma. Airflow limitation in asthma is recurrent and caused by a variety of changes in the airway. These include: Bronchoconstriction. In asthma, the dominant physiological event leading to clinical symptoms is airway narrowing and a subsequent interference with airflow.