Many people talk about pulmonary fibrosis and think it is an incurable disease, even worse than cancer, so they seek medical help everywhere, which not only delays the disease, but also causes unnecessary waste of financial resources, and the toxic side effects of various unregulated treatments add to the physical and mental pain of patients. At present, the incidence of pulmonary fibrosis seems to have an increasing trend, and there are new advances in the medical community in the understanding of pulmonary fibrosis. If you can understand the disease scientifically, you will find that pulmonary fibrosis may not be terrible. In fact, the medical term pulmonary fibrosis does not refer to just one disease, but is a collective term for a variety of diseases. To be more specific, a variety of lung diseases, as they progress, can develop into pulmonary fibrosis. For example, in most cases of nodular disease, there is no pulmonary fibrosis at the time of presentation, but in some cases it progresses and pulmonary fibrosis develops. The diagnosis of pulmonary fibrosis is often made clinically by a radiologist based on a chest radiograph or CT of the lungs, which is an examination report. Radiologists only make a report based on the image presentation, even if the “pulmonary fibrosis” is mild and not necessarily clinically significant, they will explain it in the report. After getting this report, the respiratory physician will make a clinical diagnosis based on a comprehensive analysis of the patient’s symptoms, physical examination, and other laboratory tests. It is not enough for the respiratory doctor to make the diagnosis of “pulmonary fibrosis”, but also to make further judgments about the possible types and causes of the disease. In this way, it is possible to achieve the goal of treating the disease at its root. Of course, in many clinical cases of pulmonary fibrosis, it is difficult to clarify the type and possible cause of the disease, even after extensive and in-depth examination. This is a reflection of the limitations of clinical medicine itself, and secondly, it shows that there are still many unknowns in the field of pulmonary fibrosis that need to be solved by our research. There is also a medical term very closely related to pulmonary fibrosis called “interstitial lung disease” or “interstitial lung disease”. Interstitial lung disease is a term commonly used by respiratory physicians and covers a broader range of conditions, including pulmonary fibrosis. Briefly, respiratory diseases can be divided into several major categories, including airway diseases such as asthma, chronic obstructive pulmonary disease, bronchiectasis, etc., respiratory infections such as pneumonia and tuberculosis, various lung tumors, and pleural diseases such as pleurisy; in addition, another major category is interstitial lung disease. Occupational lung diseases caused by various environmental occupational factors, pulmonary manifestations of rheumatic immune diseases, idiopathic pulmonary fibrosis, nodular disease, exogenous allergic alveolitis, and, rarely, alveolar protein deposition, all belong to the category of interstitial lung disease. Sometimes in radiology reports, you will see the term “interstitial lung changes”. Some of these interstitial lung changes may or may not be interstitial lung disease, such as mild interstitial lung changes that may remain after the lung inflammation has resolved. There are many causes of pulmonary fibrosis. Common ones are environmental, occupational, physical and chemical factors, such as asbestos, mineral dust, chemotherapeutic drugs, radiation damage, and inhalation of harmful gases. Exogenous allergic alveolitis caused by exposure to pigeon droppings, animal fur, moldy grasses, etc., can also lead to pulmonary fibrosis. Some rheumatic immune diseases, such as systemic lupus erythematosus, rheumatoid arthritis, dry syndrome, dermatomyositis, scleroderma, etc., can be accompanied by pulmonary fibrosis, and some pulmonary fibrosis even occurs before. The so-called idiopathic pulmonary fibrosis, whose etiology is still unclear and for which there is no curative and definitive treatment, is a more familiar type of pulmonary fibrosis. The common features of pulmonary fibrosis are slow onset, predominantly dry cough with little sputum, and prominent shortness of breath after activity. Shortness of breath is the most common first symptom, with chest tightness and a feeling of “not having enough air” when walking at a normal pace or walking upstairs, and progressively worsening; respiratory failure often occurs in the later stages of the disease. The diagnosis of pulmonary fibrosis requires chest radiographs, high-resolution CT examinations and lung function measurements. Some also require bronchoalveolar lavage fluid examination by bronchoscopy, and individual difficult cases even require lung biopsy by thoracoscopy or small open chest to clarify the diagnosis. In particular, it should be noted that pulmonary fibrosis is a wide variety of diseases, many of which are concomitant to other lung diseases and do not require additional testing and treatment. In clinical practice, we encounter many patients with “pulmonary fibrosis” that are not necessarily true pulmonary fibrosis as mentioned above. Since the diagnosis of pulmonary fibrosis requires extensive clinical experience and the necessary tests, we recommend that patients with suspected pulmonary fibrosis or interstitial lung disease should be seen by a respiratory clinic with experience in the diagnosis and treatment of pulmonary fibrosis.