Smooth muscle constriction results in the feeling of chest tightness.

平滑肌收缩导致胸闷感。

That said, symptoms of asthma include coughing, a feeling of chest tightness, dyspnea, or difficulty breathing, and wheezing, or a high-pitched whistling sound that usually happens during exhalation.

也就是说，哮喘的症状包括咳嗽、胸闷、呼吸困难、喘息，即呼气时伴随高调吹哨音。