Abstract
Since December 2019, more than 3 million cases of coronavirus disease 2019 (COVID-19) and about 200,000 deaths have been reported worldwide. The outbreak of this novel disease has become a global health emergency and continues to rapidly spread around the world. Based on the clinical data, approved cases are divided into four classes including mild, moderate, severe, and critical. About 5% of cases were considered critically ill and 14% were considered to have the severe classification of the disease. In China, the fatality rate of this infection was about 4%. This review focuses on currently available information on the etiology, clinical symptoms, diagnosis, and mechanism of action of COVID-19. Furthermore, we present an overview of diagnostic approaches and treatment of this disease according to available findings. This review paper will help the physician to diagnose and successfully treat COVID-19.