The sound of percussion in bronchial asthma mainly relates to the period of the attack and the different states of the disease. Generally, during the stable or non-acute phase of asthma, the percussion sound is typically dull. Of course, some patients, due to long-term poor control of asthma, may exhibit a hyperresonant percussion sound. However, during an acute asthma attack, due to a large amount of gas remaining in the lungs that cannot be exhaled, a hyperresonant percussion sound may occur. This situation generally indicates that the patient's condition is quite severe. Therefore, timely treatment should be provided, otherwise, the prolonged retention of gas in the lungs could lead to respiratory failure and even life-threatening complications.