Clinical features of COVID-19

The incubation period from exposure to symptoms is generally 7–14 days; the shortest is 1 day, the longest is up to 20 days. Fever, fatigue, and dry cough appear to be the most common symptoms at illness onset, but these symptoms, which also present in influenza and other respiratory infections, are nonspecific. Upper respiratory tract symptoms like nasal obstruction and rhinorrhea are relatively rare. In general, the majority of patients have a satisfactory prognosis with a few patients being critically ill. Fatal cases are commonly seen in the elderly and those with chronic underlying diseases, such as diabetes and heart disease.