Interstitial lung disease (ILD) is a group of heterogeneous lung diseases containing more than 200 different pathological types. Due to its insidious early symptoms and lack of specificity in clinical manifestations, diagnosis and treatment are challenging. Exhaled nitric oxide (eNO), as a biomarker in exhaled gas, has the advantages of being convenient, non-invasive and repeatable. This article starts from the biological role of nitric oxide and the pathogenesis of interstitial lung diseases, introduces the connection between NO and interstitial lung diseases, systematically and comprehensively summarizes the application of fractional exhaled nitric oxide (FeNO) and alveolar nitric oxide (CaNO) in various interstitial lung diseases in the past few years, including their value in the auxiliary diagnosis of diseases. The value in the assessment of disease severity and prognosis, as well as the value in the differentiation among various subtypes, provides new ideas for the diagnosis and treatment research of interstitial lung diseases.

间质性肺疾病（ILD）是一组包含200多种不同病理类型的异质性肺疾病，因其早期症状较隐匿且临床表现缺乏特异性，诊断和治疗具有挑战性。呼出气一氧化氮（eNO）作为呼出气体中的生物标志物，优势是便捷、无创，可重复操作。本文从一氧化氮（NO）的生物学作用及ILD的发病机制出发，介绍了NO与ILD的联系，系统、全面地归纳了既往呼出气一氧化氮检测（FeNO）及肺泡气一氧化氮检测（CaNO）在各类ILD中的应用，包括在疾病辅助诊断中的价值，在疾病严重程度及预后评估中的价值，以及各亚型间鉴别中的价值，为ILD的诊断及治疗研究提供了新的思路。