Among symptomatic COVID-19 patients, cough, myalgia, and headache are most common. Other symptoms such as diarrhea, sore throat, and abnormal sense of smell or taste have been reported numerous times.
Mild upper respiratory symptoms (e.g., nasal congestion, sneezing) may be more common in Delta and Omicron variant infections. Pneumonia is the most common serious manifestation of infection, characterized by fever, cough, dyspnea, and bilateral lung infiltrate images. Although COVID-19 causes certain clinical features (especially smell or taste disturbances) more often than in other viral respiratory infections, no single symptom or sign clearly identifies COVID-19.
Another subset of patients, asymptomatically infected, i.e., infected with the new coronavirus but showing no clinical symptoms, are insidious and can only be detected by nucleic acid testing, and remain highly contagious.
During the widespread epidemic, it is recommended to take good personal protection, wash hands frequently, maintain a certain social distance, and seek prompt medical attention if there are relevant symptoms.