COVID-19 vs. Flu

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COVID-19 vs. Flu: All the Similarities and Differences to Know

COVID-19 vs. Flu: All the Similarities and Differences to Know

There are key similarities and differences
COVID-19 vs. Flu

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Flu season in the U.S. lasts from fall through winter. During a usual year, cases peak sometime between December and February and taper off by May. This year, as flu season coincides with the coronavirus pandemic, there are several key similarities and 10 differences to know between the two illnesses.

Similarity: COVID-19 and the flu are both contagious respiratory illnesses

Similarity: COVID-19 and the flu are both contagious respiratory illnesses

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First off, COVID-19 and the flu are both contagious respiratory illnesses, meaning they can be spread from an infected person or a noninfected person and affect a person's lungs and respiratory system.

Difference: Each is caused by a different virus

Difference: Each is caused by a different virus

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While both are contagious respiratory illnesses, the flu and the coronavirus are caused by different viruses. Infection with a new coronavirus called SARS-CoV-2 causes COVID-19. Year-round, different types and subtypes of influenza viruses circulate. The flu is caused by infection with any type of influenza virus.

Similarity: Both illnesses cause similar symptoms

Similarity: Both illnesses cause similar symptoms

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Flu and COVID-19 symptoms are incredibly similar. Both illnesses may cause fever or a feverish feeling, shortness of breath, difficulty breathing, cough, sore throat, runny or stuffy nose, fatigue, tiredness, muscle pain or body aches and headaches. Vomiting and diarrhea are also common symptoms in children but not adults. COVID-19 and flu patients both exhibit these symptoms to varying degrees, from no symptoms to severe ones.

Difference: Only COVID-19 causes loss of taste and smell

Difference: Only COVID-19 causes loss of taste and smell

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Change or loss of taste or smell are two symptoms that set COVID-19 apart from the flu. However, given the many similar symptoms, it is difficult to tell the difference between the two based on symptoms alone. Anyone considering testing to determine which virus they have can look to the Centers for Disease Control and Prevention coronavirus self-checker for advice based on symptoms.

Difference: COVID-19 appears to cause more severe illness

Difference: COVID-19 appears to cause more severe illness

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Although resulting in similar sorts of symptoms, COVID-19 does seem to cause more serious illnesses in some people than the flu. Accordingly, anyone experiencing severe COVID-19 symptoms like trouble breathing, confusion, bluish facial features, an inability to wake or stay awake or persistent pain or pressure in the chest should seek emergency medical care immediately.

Similarity: In both cases, symptoms may take time to appear

Similarity: In both cases, symptoms may take time to appear

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It could take a day or more following infection for a person to begin experiencing symptoms of either the flu or COVID-19. Usually, a person infected with the flu develops symptoms one to four days after infection. A person infected with COVID-19 typically develops symptoms five days after infection.

Difference: COVID-19 symptoms may take even longer to appear

Difference: COVID-19 symptoms may take even longer to appear

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While five days is typical, a person infected with COVID-19 may begin developing symptoms anywhere between two and 14 days after infection. Anyone who believes they may have contracted COVID-19 should contact a health care provider, start tracking symptoms and wear a mask around other people and pets, even at home.

Similarity: Both illnesses can be spread before a patient shows symptoms

Similarity: Both illnesses can be spread before a patient shows symptoms

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Even if they are not exhibiting signs or symptoms, a person with the flu or COVID-19 can still be contagious. In most cases, people with the flu are contagious for about a day before showing symptoms. People with COVID-19 are contagious for about two days before showing symptoms.

Difference: COVID-19 patients may be contagious for longer

Difference: COVID-19 patients may be contagious for longer

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Adults and older children who contract the flu are often contagious for the first day without symptoms, for three or four days of the illness and up to a week after. It’s possible for people with COVID-19 to spread the virus the two days before symptoms show and at least 10 days after. However, researchers are still working to understand how long a person with COVID-19 is contagious.

Similarity: Both the flu and COVID-19 are spread by air droplets

Similarity: Both the flu and COVID-19 are spread by air droplets

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Just like COVID-19, the flu is spread by close contact between two people. Air droplets released when an infected person sneezes, coughs or talks land on nearby people who potentially inhale them.

Difference: Superspreader events more commonly spread COVID-19

Difference: Superspreader events more commonly spread COVID-19

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Unlike the flu, COVID-19 has been known to have more superspreader events, instances when a single person in attendance infects many more. This results in continuous virus spread over time and points to COVID-19’s easy transferability.

Similarity: Both illnesses may be spread by physical contact

Similarity: Both illnesses may be spread by physical contact

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It is possible for people to contract both illnesses via physical human contact like shaking hands or giving high-fives. Less commonly, a person can also get the flu or coronavirus by touching their face after touching a surface or object with the virus on it.

Similarity: Both COVID-19 and the flu share common complications

Similarity: Both COVID-19 and the flu share common complications

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The flu and COVID-19 share several common severe complications, including pneumonia, heart attacks and strokes, respiratory failures, inflammation, bacterial infections, sepsis and fluid in lungs and more.

Difference: COVID-19 may cause more severe complications

Difference: COVID-19 may cause more severe complications

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COVID-19 may cause other severe complications in adults too. After a coronavirus diagnosis, people may develop blood clots in the veins and arteries of the lungs, legs, heart or brain.

Similarity: Older adults and others are at higher risk for both

Similarity: Older adults and others are at higher risk for both

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Older adults, pregnant people and people with existing health conditions are all at higher risk for severe illness after contracting either COVID-19 or the flu. To avoid contracting the coronavirus, those in these at-risk categories should limit contact with other people as much as possible and take precautions to reduce virus spread.

Difference: Children are at higher risk for severe flu complications

Difference: Children are at higher risk for severe flu complications

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Any child under 5 years old, no matter how healthy, is at high risk for serious flu complications. Those under 2 years old are at even higher risk. Common severe complications caused by the flu include pneumonia, dehydration and long-term health problems like asthma and heart disease.

Difference: Kids with COVID-19 can contract MIS-C

Difference: Kids with COVID-19 can contract MIS-C

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When infected with COVID-19, school-aged children are at a higher risk of multisystem inflammatory syndrome. Also called MIS-C, this severe condition results in varying body parts becoming inflamed, including the lungs, kidneys, heart and brain. Much is still to be learned about MIS-C, but the condition of most children who have been diagnosed with MIS-C has improved with medical care.

Similarity: Neither COVID-19 nor the flu is treatable with antibiotics

Similarity: Neither COVID-19 nor the flu is treatable with antibiotics

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Antibiotics only work for certain bacterial infections. Accordingly, both the flu and COVID-19, two viral infections, cannot be treated with antibiotics. Instead, both COVID-19 and the flu are treated by addressing key symptoms.

Similarity: The duration of both illnesses may be shortened by antiviral medicine

Similarity: The duration of both illnesses may be shortened by antiviral medicine

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Although not treatable by antibiotics, both the duration of the flu and COVID-19 can be shortened with some help from antiviral medications. These sorts of drugs are not sold over the counter and require a prescription from a healthcare provider. However, for mildly sick people, staying hydrated and over-the-counter drugs like acetaminophen (Tylenol) for COVID-19 and ibuprofen for the flu are helpful.

Difference: Flu shots are available, while COVID-19 vaccines are in the works

Difference: Flu shots are available, while COVID-19 vaccines are in the works

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