Uneventful breath may be caused by over-excited emotions, or it may be caused by pathologic factors, such as asthma, pulmonary heart disease, and so on. 1. Over-excited: if the patient is emotionally agitated and often in a state of tension and anxiety, leading to increased and rapid breathing, respiratory alkalosis may occur, which may lead to chest tightness, shortness of breath, breathlessness and other symptoms. 2. Asthma: If the patient suffers from asthma and is in the acute stage, then due to the spasm of bronchial smooth muscle, increased secretion, etc., leading to chest tightness, shortness of breath, breathlessness and other symptoms when the patient is active. 3. Pulmonary heart disease: if the patient suffers from pulmonary heart disease, when pulmonary stasis occurs, there will be blood and fluid seepage in the lung tissues, resulting in the normal function of gas exchange being affected, which will lead to the emergence of breathlessness. If the patient has the symptom of poor air quality, it is recommended that the patient go to the hospital in time to improve the chest X-ray, bronchodilatation test, electrocardiogram and other tests, to clarify the cause of the disease, and comply with the doctor’s instructions for treatment.