The answer to this question is first of all yes, almost all types of interstitial pneumonia require a lung biopsy to obtain a more definitive diagnosis, which is determined by the characteristics of interstitial pneumonia itself. Idiopathic interstitial pneumonia includes many types, each with its own unique clinical, imaging, and pathological changes, but neither the clinical symptoms, nor the signs are specific, and the diagnosis of interstitial pneumonia cannot be given based on these alone; the same is true of imaging, as there is more crossover between idiopathic interstitial pneumonia, and although pathology has a greater role in establishing the diagnosis, if it is a small, For example, in the more common mechanized pneumonia, such pathological changes can appear around lung cancer tissue and can appear in the pathological manifestations of tuberculosis, pneumonia, inflammatory pseudotumor, vasculitis, fungal infection, etc. If small, single-point biopsies show such changes, they do not reflect the characteristics of these diseases; another example is The pathology of acute interstitial pneumonia (AIP) is characterized by diffuse alveolar damage, which is not unique to AIP, but also occurs in another serious disease, ARDS, where the diagnosis requires a combination of clinical, imaging, and pathology. The question of when a biopsy is indicated is a very simple yet complex one. It is simple because as long as the diagnosis is not particularly clear, all patients need pathologic support and therefore require biopsy at this time. It is complicated because idiopathic interstitial pneumonia is a rare disease and each physician’s knowledge of it is not the same. Even in the more typical cases, because of the rarity, it is still a difficult diagnosis for some physicians; for others, they may be able to give a definitive diagnosis based on clinical and imaging studies, without the need for biopsy. The latest guidelines state that in patients with idiopathic pulmonary fibrosis, if the clinical and imaging studies are particularly typical and other similar diseases can be excluded, the diagnosis can be established without biopsy tissue specimens.