Many patients are confused by the medical names of bronchiectasis, emphysema and COPD. They are often asked, so I think it is necessary to explain them here to help you understand. The Department of Pulmonary Diseases, Chengdu University of Traditional Chinese Medicine Hospital, He Chengsi should know that the name of a disease is given by human beings themselves. The disease itself does not give itself a name. It is entirely possible for the naming of a disease to change as our understanding continues to grow. In the early days of disease naming, the main idea was to let people understand the main features of the disease as soon as they heard the name of the disease. For example, the name of the common disease “hypertension” immediately suggests that the patient’s blood pressure is above normal. But the medical profession is not satisfied with this, but also from the cause of “primary hypertension” and “secondary hypertension”, primary means that the cause is not clear so far; secondary means that secondary to other diseases such as kidney disease, hyperthyroidism etc. 1. Chronic bronchitis. It is short for chronic bronchitis. Chronic bronchitis is a chronic non-specific inflammation of the trachea, bronchial mucosa and surrounding tissues. Clinically, cough and sputum are the main symptoms, and the onset lasts for 3 months every year for 2 years or more. Other diseases with symptoms of cough, cough and wheezing were excluded (e.g. tuberculosis, pneumoconiosis, lung abscess, heart disease, cardiac insufficiency, bronchiectasis, bronchial asthma, chronic nasopharyngitis, esophageal reflux syndrome and other disorders). This only points out the time and does not include what causes it, so the concept is rather crude and general. 2. Emphysema. This name is well known to the Chinese people. In fact, now it seems to be a pathological anatomical name. Generally speaking, emphysema verbally refers mostly to chronic obstructive pulmonary emphysema, in addition to senile emphysema, compensatory emphysema, interstitial emphysema, focal emphysema, paracentral emphysema, obstructive emphysema, etc. Emphysema is a pathological condition in which the airways at the distal end of the terminal fine bronchi (respiratory fine bronchi, alveolar ducts, alveolar sacs and alveoli) are hypoelastic, hyperinflated, inflated and have increased lung volume or are accompanied by destruction of the airway walls. Nowadays, emphysema is less often used as a clinical diagnostic name. 3, chronic obstructive pulmonary disease (COPD). COPD is a common preventable and treatable persistent, progressive, and incompletely reversible airflow limitation disease, often associated with a chronic inflammatory response of the airways and lungs to harmful particles or gases, with acute exacerbations and comorbidities affecting the severity of the disease. It is essentially a chronic inflammatory disease of the airways. COPD is characterized by airflow limitation, which is not completely reversible and progresses progressively, and is associated with an abnormal inflammatory response of the lungs to harmful gases or particles such as cigarette smoke. In patients with chronic cough, if there are risk factors for smoking or indoor or outdoor air pollution, pulmonary function tests should be performed to determine the presence or absence of airflow limitation. COPD can be diagnosed if airflow limitation exists and can be excluded from known etiologies of airflow limitation. There is a very close association with chronic bronchitis and emphysema, and COPD was often considered in the past to be chronic bronchitis with airflow limitation and/or In the past, COPD was often considered to be chronic bronchitis and/or/ or emphysema with airflow restriction, such as in the draft guidelines for the diagnosis and treatment of COPD in China as early as 1997, where the statement “COPD is chronic bronchitis or emphysema characterized by airflow obstruction, which is progressive but partially reversible and can be accompanied by airway hyperresponsiveness” was made. However, with the deepening of understanding, especially with the widespread use of standardized pulmonary function tests, it was found that chronic cough and sputum often precede airflow limitation, but not all patients with cough and sputum develop COPD, so the definition of COPD no longer includes chronic bronchitis and emphysema. It is also clearly stated that COPD can only be diagnosed when airflow limitation is present and not fully reversible on pulmonary function tests, and if a patient has only “chronic bronchitis” or “emphysema” without airflow limitation, COPD cannot be diagnosed. In other words chronic bronchitis is the most common cause of COPD, but not all chronic bronchitis develops into COPD; chronic bronchitis and emphysema without airflow limitation are not COPD. 4. Bronchial asthma. Chronic bronchitis, emphysema, COPD, and asthma can all have chronic cough, sputum, and shortness of breath as their main manifestations. Not only are they most confusing to non-medical professionals, but they are actually not easily distinguishable to many medical professionals. They all have in common chronic inflammatory airway diseases. However, in terms of the mechanism of inflammation, laryngitis, emphysema and COPD are mostly chronic inflammation caused by irritating smoke such as cigarettes and toxic particles, while asthma is chronic inflammation caused by allergic substances. Airflow limitation in COPD on pulmonary function tests is not fully reversible even with bronchodilator medications; whereas airflow limitation in asthma is fully reversible. In some patients, asthma and COPD can co-exist. History and pulmonary function tests can help to diagnose and differentiate between the two. If a patient with a previous clear diagnosis of asthma now has irreversible airflow limitation, the diagnosis may be “bronchial asthma” because irreversible airflow limitation may be due to airway remodeling. Similarly, a patient with asthma who smokes or inhales noxious gases in addition to his or her original asthma and develops irreversible airflow limitation, showing airway inflammation similar to COPD, can be diagnosed as having asthma combined with COPD, and if the COPD patient is exposed to allergens and has a reversible decrease in airflow obstruction and a positive bronchodilator test, the patient can be diagnosed as having COPD combined with asthma. In conclusion, the relationship between asthma and COPD is complex, and sometimes it is not easy to identify them clinically. The good thing is that the treatment of the two is similar in many aspects. With the progress of medicine, these terms will certainly be adjusted to new ones.