Identifying the difference between the cold, influenza, and coronavirus can be difficult because most of their symptoms are the same. But there are some different symptoms to separate them.
Cold symptoms are mild and the common cold tends not to be associated with fever or headache.
Congestion/runny nose is common for the common cold and would be uncommon to be the only symptom for influenza. Congestion/runny nose can be a symptom of a COVID infection and might be the only symptom in mild cases.
Flu symptoms are often of rapid onset. COVID symptoms can be of rapid or more gradual onset.
Says Washer, one symptom that is more unique to a COVID infection is the loss of taste or smell. And symptoms from the delta variant are similar to prior versions of COVID.
COVID-19 is also more contagious and can spread much faster than influenza. People with COVID-19 may also experience a more severe lung infection. People with COVID-19 are at greater risk of dying either during or after infection. In children, COVID-19 can cause a rare, but serious multi-system inflammatory syndrome.