Influenza (Flu) and COVID-19 are both contagious respiratory illnesses, but they are caused by different viruses. COVID-19 is caused by infection with a new coronavirus (called SARS-CoV-2) and flu is caused by infection with influenza viruses. Because some of the symptoms of flu and COVID-19 are similar, it may be hard to tell the difference between them based on symptoms alone, and testing may be needed to help confirm a diagnosis. Flu and COVID-19 share many characteristics, but there are some key differences between the two.
Both COVID-19 and flu can have varying degrees of signs and symptoms, ranging from no symptoms (asymptomatic) to severe symptoms. Common symptoms that COVID-19 and flu share include:
- Fever or feeling feverish/chills
- Shortness of breath or difficulty breathing
- Fatigue (tiredness)
- Sore throat
- Runny or stuffy nose
- Muscle pain or body aches
- Some people may have vomiting and diarrhea, though this is more common in children than adults
Flu viruses can cause mild to severe illness, including common signs and symptoms listed above.
COVID-19 – other signs and symptoms of COVID-19, different from flu, may include change in or loss of taste or smell.
How long symptoms appear after exposure and infection
For both COVID-19 and flu, 1 or more days can pass between a person becoming infected and when he or she starts to experience illness symptoms.
If a person has COVID-19, it could take them longer to develop symptoms than if they had flu.
Flu – Typically, a person develops symptoms anywhere from 1 to 4 days after infection.
COVID-19 – Typically, a person develops symptoms 5 days after being infected, but symptoms can appear as early as 2 days after infection or as late as 14 days after infection, and the time range can vary.
For more information on the difference of the flu and COVID-19 visit https://www.cdc.gov/flu/symptoms/flu-vs-covid19.htm