Asthma

Once thought to be an acute, sporadic illness, asthma is now understood to be a chronic, inflammatory lung process which is becoming increasingly common across the globe. Generally the diagnosis is made when the patient, usually a child, presents to the health care provider with wheeze, cough, and/or breathlessness which is not accompanied by an acute illness. The diagnosis is not made, however, on the first presentation, but at the second or third, with the patient having normal respiration at other points in time, and the chronic nature of the ailment can be established.

The chronic inflammation causes the interior wall of the airways to become swollen, reddened, with increased mucus production. This causes the lumen of the airway to narrow, and the wall itself becomes more irritable and responds easily to irritants. This response takes the form of bronchoconstriction (tightening of the muscles which circle the smallest airway bronchioles). While the bronchoconstriction is reversible...