What is a common hallmark symptom of asthma?

Wheezing is a common hallmark symptom of asthma due to the narrowing of the airways. In asthma, inflammation and bronchoconstriction occur, which leads to increased airway resistance, especially during expiration. This results in a characteristic high-pitched whistling sound known as wheezing. This sound is typically more prevalent during exhalation, but it can also be heard during inhalation in more severe cases.

In contrast, pneumonia typically presents with different symptoms, such as productive cough, fever, and localized chest pain, rather than wheezing. Expiratory grunting is more associated with conditions like severe respiratory distress in infants and does not specifically indicate asthma. While tachypnea, or rapid breathing, can occur in asthma during exacerbations, it is a more general response seen in various respiratory conditions and is not as specific as wheezing. Thus, wheezing stands out as a definitive and identifying feature of asthma.