2.1
Asthma is a common disease that produces symptoms of wheezing and breathlessness. It affects the lower airways and results in narrowing (bronchoconstriction) of the airways with consequent reduction in the flow of gases between the airways and lung alveoli. It can be triggered by a variety of environmental factors such as infection, allergy, airborne chemicals and also exercise. There are a number of patterns of lower airways disease in early childhood that results in 2 predominant clinical patterns (acute wheezy episodes and recurrent day to day symptoms) that may occur separately or together in the child.