Determining the cause of an illness can be tricky because many share some symptoms. They can leave you sniffling, coughing, and feeling tired. But there are important differences.
Figuring out what’s making you sick can help you recover and prevent spreading sickness to others.
Flu vs COVID-19
“Distinguishing COVID from flu can be difficult because the symptoms overlap so much,” explains Dr. Brooke Bozick, an NIH expert on respiratory diseases that affect the lungs.
Flu and COVID-19 are caused by different viruses that can be spread among people. Flu is caused by the influenza virus. COVID-19 is caused by SARS-CoV-2. Both can give you a fever, cough, headaches, and body aches.
Flu and COVID-19 also spread similarly. They’re transmitted by small particles that come from your nose and mouth when you sneeze, cough, sing, or talk, raising the possibility of infecting people who are nearby. Infected people may not have symptoms, but can still pass along either virus.
“Both influenza and COVID can be spread to other people before individuals develop symptoms,” notes Dr. Aubree Gordon, an infectious disease expert at the University of Michigan.