Long COVID (also known as "post-acute sequelae of COVID-19") is a multi-system disorder that follows an acute bout of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection [1]. Although its exact prevalence is unknown, it is estimated to affect approximately 10% of SARS-CoV-2-infected individuals, though in reality the proportion is likely much higher owing to under-reporting of cases [1]. The prevalence is elevated in patients who have had acute SARS-CoV-2 pneumonia requiring hospitalisation, and lower in those who have been previously vaccinated or were infected with the Omicron variant [1]. In approximately 6% of the cases of long COVID, pulmonary symptoms such as dyspnoea, cough and wheeziness are prominent, leading to considerable disability and morbidity [2, 3]. While it is attractive to view long COVID as one disease, it is likely a very complex, heterogeneous disorder, with multiple different phenotypes, each driven by a unique set of molecules and pathways [1]. Even within an organ system (e.g. the lungs), there is likely to be significant heterogeneity in the phenotypes of disease. Here, we hypothesise that patients with long COVID with a predominance of pulmonary symptoms (which we will refer to in this viewpoint editorial as "pulmonary long COVID", or PLC) have airway pathology that can be detected using conventional as well as emerging technologies, and careful phenotyping of this condition will provide important insights on its mechanism(s) and reveal novel biomarkers and therapeutic solutions for millions around the world with PLC.

长新冠肺炎（也称为“COVID-19 急性后遗症”）是严重急性呼吸综合征冠状病毒 2 (SARS-CoV-2) 感染急性发作后出现的一种多系统疾病 [1]。尽管其确切患病率尚不清楚，但估计约 10% 的 SARS-CoV-2 感染者受到影响，但实际上由于病例报告不足，这一比例可能要高得多 [1]。在患有需要住院治疗的急性 SARS-CoV-2 肺炎的患者中，患病率较高，而在之前接种过疫苗或感染过 Omicron 变种的患者中，患病率较低[1]。在大约 6% 的长期新冠病例中，呼吸困难、咳嗽和喘息等肺部症状很明显，导致相当大的残疾和发病率 [2, 3]。虽然将长期新冠病毒视为一种疾病很有吸引力，但它可能是一种非常复杂、异质的疾病，具有多种不同的表型，每种表型均由一组独特的分子和途径驱动[1]。即使在器官系统（例如肺）内，疾病的表型也可能存在显着的异质性。在这里，我们假设以肺部症状为主的长期新冠肺炎患者（我们在这篇观点社论中将其称为“肺长期新冠肺炎”或 PLC）具有可以使用传统技术和新兴技术检测到的气道病理学，对这种疾病的仔细表型分析将为其机制提供重要见解，并为全世界数百万人的 PLC 揭示新的生物标志物和治疗解决方案。