What Causes Exercise Induced Bronchospasm

Exercise-induced bronchospasm is caused by the loss of heat, water, or both from the lungs during exercise, stemming from hyperventilation of air that is drier and cooler than that in the respiratory tree. Between 80 and 90 percent of patients with asthma also have EIB.

Why does exercise-induced bronchoconstriction happen?

When you exercise, you breathe faster and deeper due to the increased oxygen demands of your body. You usually inhale through your mouth, causing the air to be dryer and cooler than when you breathe through your nose. The dry and/or cold air is the main trigger for airway narrowing (bronchoconstriction).

Is EIB the same as asthma?

Exercise-induced bronchoconstriction (also called EIB) or exercise-induced asthma, is a narrowing of the airways that makes it hard to move air out of the lungs. Asthma is a disorder involving inflammation in the lungs associated with narrowing of the airways.