ABSTRACT
The novel pandemic, coronavirus disease 2019 (COVID-19), is a public health exigency of global concern with expanding cases worldwide. Severe acute respiratory syndrome-corona virus-2 is the virus that accounts for COVID-19. The disease manifests with a wide array of symptoms ranging from mild upper respiratory tract infection to severe pneumonia and death. The Happy hypoxemia, synonymously Silent hypoxemia, is described as a clinical entity in individuals with COVID-19, generally expressed as objective hypoxemia lacking respiratory distress symptoms. The condition is characterized by a drop in oxygen saturation and varying arterial blood gas. Intrapulmonary shunting, intravascular microthrombi, loss of lung perfusion control, and impaired diffusion capacity contributes to hypoxemic etiology in COVID-19. The ventilation-perfusion mismatch, covering from shunts to alveolar dead space ventilation, is the principal distinctive feature, suggesting numerous medical goals. © 2022. Chithira V. Nair et al. This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/).