Pulmonary Sequelae in Long COVID: Current Evidence and Clinical Perspectives, a State-of-the-Art Review

Abstract

Context: Long COVID has emerged as a major cause of persistent respiratory symptoms and functional impairment after acute SARS-CoV-2 infection. Pulmonary involvement is among the most common long-term manifestations and may affect both previously hospitalized and non-hospitalized individuals. However, the clinical presentation, physiologic abnormalities, and radiologic findings remain highly heterogeneous. Evidence Acquisition: This state-of-the-art narrative review synthesizes current evidence on the pulmonary sequelae of Long COVID. Literature searches were conducted in PubMed/MEDLINE, Scopus, and Google Scholar for studies published between January 2020 and May 2026, focusing on persistent respiratory symptoms, imaging abnormalities, pulmonary function impairment, exercise limitation, rehabilitation, and management strategies following acute COVID-19. Evidence was critically synthesized with emphasis on study quality, methodological rigor, and clinical relevance. Results: Dyspnea and exercise intolerance are among the most frequently reported manifestations of pulmonary Long COVID. Reduced diffusion capacity (DLCO) is the most common functional abnormality, whereas spirometric findings are often normal or only mildly impaired. Imaging studies may demonstrate persistent ground-glass opacities, reticulations, or fibrotic-like abnormalities, although many radiologic changes improve over time. Notably, symptom severity often correlates poorly with radiologic and physiologic findings, suggesting a multifactorial pathophysiology involving inflammatory, microvascular, immune-mediated, autonomic, and functional mechanisms. Considerable heterogeneity exists across studies owing to differences in patient populations, disease severity, vaccination status, viral variants, and follow-up duration. Pulmonary rehabilitation shows the most consistent evidence of clinical benefit, whereas evidence supporting disease-modifying pharmacologic therapies remains limited. Conclusions: Pulmonary Long COVID is a heterogeneous clinical syndrome that cannot be fully explained by residual structural lung injury alone. Comprehensive multidisciplinary assessment integrating symptom evaluation, pulmonary function testing, imaging, and functional assessment is essential for accurate characterization and individualized management. Future progress will depend on improved risk stratification, deeper mechanistic understanding, standardized outcome measures, and adequately powered longitudinal and interventional studies.