Patients who are always out of breath can be seen with respiratory system diseases or cardiovascular system diseases. If the patient has never been seen before, it is recommended to first go to the respiratory or cardiovascular department, and under the guidance of the doctor, conduct the appropriate examination to further confirm the diagnosis, as follows: a. Respiratory diseases: the most common causes of constant breathlessness are acute attacks of chronic wheezing bronchitis, acute attacks of bronchial asthma, acute attacks of cough or chest tightness variant asthma, acute exacerbation of chronic obstructive pulmonary disease , acute exacerbation of interstitial lung disease, etc. In addition, it can be seen in pulmonary embolism, pneumothorax and other acute and critical diseases. Second, cardiovascular system diseases: the most common are acute heart attack, coronary heart disease, angina pectoris, heart failure and other diseases. Therefore, old breathlessness can be due to respiratory system diseases, but also due to cardiovascular system diseases. If this happens, you should go to the hospital and see a respiratory or cardiovascular department to do the appropriate tests to further confirm the diagnosis and take treatment.