Similarities:
Both COVID-19 and flu can have varying degrees of symptoms, from no symptoms (asymptomatic) to severe symptoms. Common symptoms shared by COVID-19 and the flu include:
- Fever or feeling hot/chills
- Cough
- Shortness of breath or difficulty breathing
- Fatigue (fatigue)
- Throat ache
- Runny or stuffy nose
- Muscle pain or body aches
- Headache
- Vomiting
- Diarrhea
- Change or loss of taste or smell, although more common with COVID-19.
Both COVID-19 and flu can spread from person to person (within about 6 feet) between people who are in close contact with each other. Both are mainly spread by large and small particles containing the virus that are expelled when people with the disease (COVID-19 or the flu) cough, sneeze or talk. These particles can land in the mouths or noses of people nearby and possibly be inhaled into their lungs. In some cases, such as indoor settings with poor ventilation, small particles can spread more than 6 feet away and cause infections.
Although most spread is by respiratory route, it may be possible for a person to become infected by touching another person (for example, by shaking hands with someone who has the virus) or by touching a surface or object that has the virus on it. and then touching their own mouth, nose, or eyes.
both flu viruses and the virus that causes COVID-19 can infect others before people start showing symptoms; by people with very mild symptoms; and by persons who have never experienced symptoms (asymptomatic persons).
Differences:
While the virus that causes COVID-19 and influenza viruses are thought to spread in similar ways, the virus that causes COVID-19 is generally more contagious than flu viruses. It has also been observed that COVID-19 has more spread events than the flu. This means that the virus that causes COVID-19 can spread quickly and easily to many people, causing continued spread among people as time goes on.
Overall, COVID-19 seems to cause more serious illness in some people. Serious COVID-19 illness resulting in hospitalization and death can occur even in healthy people. Some people with COVID-19 may go on to develop post-COVID conditions or multisystem inflammatory syndrome (MIS).