What is the main characteristic of asthma in relation to airflow?

The primary characteristic of asthma in relation to airflow is that individuals experience difficulties in exhaling, which is accurately reflected in the choice. Asthma is characterized by inflammation and narrowing of the airways, which leads to increased resistance to airflow during expiration. This resistance can result in wheezing, shortness of breath, and coughing, particularly when airflow is forced out of the lungs.

When a person with asthma attempts to exhale, the constricted airways can make it challenging for air to leave the lungs efficiently. This phenomenon is often measured in pulmonary function tests, where a reduced forced expiratory volume (FEV1) indicates compromised airflow during exhalation. Thus, the difficulty primarily manifests when attempting to expel air, rather than when drawing air in.

In contrast, while asthma can have varying degrees of impact on small and large airways, it is not restricted to only one size of airway. Additionally, stable airflow with no issues does not apply to asthma, as it is inherently a condition marked by intermittent episodes of airflow obstruction.