Physiological Changes Following COVID-19 Infection: A Narrative Review

Abstract

Coronavirus disease 2019 (COVID-19), caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), has affected millions worldwide. Although many patients recover completely, a substantial proportion continue to experience persistent physiological alterations involving multiple organ systems. These long-term consequences, commonly referred to as post-COVID syndrome or Long COVID, affect respiratory, cardiovascular, neurological, endocrine, musculoskeletal, renal, gastrointestinal, and immune functions. Persistent inflammation, endothelial dysfunction, immune dysregulation, mitochondrial impairment, and microvascular injury are considered major mechanisms underlying these physiological changes. Understanding these alterations is essential for effective diagnosis, rehabilitation, and long-term patient management. This review summarizes the current evidence regarding the physiological changes observed after COVID-19 infection and discusses the potential mechanisms responsible for these persistent effects.