After exposure to asthma triggers, symptoms rarely develop abruptly but progress over a period of hours or days. In some cases, the airways have become seriously obstructed by the time the patient even calls the doctor. Wheezing when breathing out is nearly always present during an attack. Usually the attack begins with wheezing and rapid breathing, and, as it becomes more severe, all breathing muscles become visibly active. The severity of shortness of breath does not necessarily reflect the severity of the attack.
Some people experience severe dyspnea but have adequate lung function.
On the other hand, some others may not perceive their breathing as very impaired but actually have very low lung function. In some people the first symptom is a nonproductive cough or chest tightness or pain that is not associated with wheezing. Tightness in the chest. If tightness is the primary symptom, it may be an early indicator of a serious attack. Rapid heart rate.