Abstract: Severe interstitial lung disease (SILD) is a large group of complex and rapidly progressing diseases with an extremely high mortality rate. Early diagnosis, assessment and treatment of patients with SILD are of critical importance. The application of quantitative computed tomography (QCT), positron emission tomography/computed tomography (PET/CT) and bronchoalveolar lavage fluid metagenomic next-generation sequencing (BALF-mNGS) in the diagnosis of SILD holds promise for improving diagnostic rates and accuracy. Glucocorticoids/immunosuppressants serve as the cornerstone of treatment, while tofacitinib, antifibrotic drugs and hypoxia management play significant roles in improving patient prognosis. However, continuous research and the development of individualized treatment strategy are still necessary to provide more solid evidence and more diverse options for clinical practice.

Key words: interstitial lung disease, acute exacerbation, pulmonary fibrosis, diagnosis, treatment