COVID-19: A threat to the respiratory system.

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), causes acute coronavirus disease-19 (COVID-19) that has emerged on a pandemic level. Coronaviruses are well-known to have a negative impact on the lungs and cardiovascular system. SARS-CoV-2 induces a cytokine storm that primarily targets the lungs, causing widespread clinical disorders, including COVID-19. Although, SARS-CoV-2 positive individuals often show no or mild upper respiratory tract symptoms, severe cases can progress to acute respiratory distress syndrome (ARDS). Novel CoV-2 infection in 2019 resulted in viral pneumonia as well as other complications and extrapulmonary manifestation. ARDS is also linked to a higher risk of death. Now, it is essential to develop our perception of the long term sequelae coronavirus infection for the identification of COVID-19 survivors who are at higher risk of developing the chronic lung fibrosis. This review study was planned to provide an overview of the effects of SARS-CoV-2 infection on various parts of the respiratory system such as airways, pulmonary vascular, lung parenchymal and respiratory neuromuscular system as well as the potential mechanism of the ARDS related respiratory complications including the lung fibrosis in patients with severe COVID-19.