Under the Weather? Know the Difference Between Covid-19 and the Flu

Winter is coming, and so is the annual flu season. It might have been easy to forget about this seasonal virus, since Covid-19 has been the main focus in America for almost two years now, but it hasn’t gone anywhere, and experts are predicting a pretty severe flu season this year. So if you wake up one morning this winter with symptoms like a stuffy nose, fever, and cough, you’ll have to consider whether you might have a case of the flu or of Covid, since both are contagious respiratory illnesses that share similar symptoms. If you are feeling under the weather, it is important to differentiate the symptoms of these viruses, so you can get tested for Covid if need be, and get the proper treatment. 

The Difference Between the Flu Virus & the Covid Virus2 different colored viruses floating around

As stated earlier, the flu and Covid are both contagious respiratory viruses, but they are caused by different viruses. The flu is caused by the influenza virus, usually influenza A or influenza B, while  Covid-19 is caused by a coronavirus known as SARS-CoV-2; this is a novel coronavirus, meaning it has not been seen in humans before now. Because our bodies were never exposed to this virus before 2019, we have not built any antibodies to fight it, which is why the outbreak of this virus has become a global pandemic. 

While the flu cannot turn into Covid, and Covid cannot turn into the flu because they are two different viruses, it is possible to be infected with both at the same time. It’s important to remember that both Covid and the flu can result in severe illness and complications, especially for older adults, people with underlying medical conditions, and pregnant people. Covid-19 can result in long-term damage to the heart, kidneys, brain, and lungs, and the flu can lead to complications such as inflammation of the heart, brain, or muscle tissue, and can even lead to multi-organ failure. 

How Are These Viruses Spread?

Both the flu and Covid spread in similar ways: droplets of small virus particles from a sick person that are transmitted to another person through talking, coughing, sneezing, etc. You can also transfer the virus by touching a surface with germs on it and then touching your face, although most experts believe that Covid is mostly spread through respiratory droplets. Covid-19 spreads more easily than the flu and can cause more serious illness in some people. 

How Long Is the Incubation Period?

calendar up close
Flu symptoms can occur 1-4 days after infection, while Covid symptoms will probably appear around 5-14 days after.

It tends to take longer after infection for someone to experience symptoms of Covid than it does with the flu. If you are infected with the flu, you will most likely experience symptoms anywhere from 1 to 4 days after infection, while if you are infected with Covid, your symptoms will probably appear around 5 days after infection; in some cases, symptoms will not appear until 14 days after infection. Symptoms will vary from person to person, so if you have fever, cough, shortness of breath, sore throat, fatigue, confusion, headache, runny nose, or loss of taste or smell, it is important to get tested for Covid.

How Long Are You Contagious?

If you are infected with either Covid or the flu, it’s possible to spread these viruses before experiencing any symptoms. People with the flu are contagious for one day before they show symptoms; older children and adults appear to be most contagious during the initial 3 or 4 days of their illness, but remain contagious for a week. If you are infected with Covid, you could be contagious for a longer time than if you have the flu; it can also take longer  to show symptoms, and you could be contagious earlier than 1 day before symptoms begin.

Similarities & Differences Between Covid & Flu Symptoms


Many respiratory illnesses share similar symptoms: when bacteria or viruses get into your respiratory system, the whole system, including your airways, lungs, and blood vessels, is affected, resulting in similar symptoms for a head cold, the flu, and Covid. Some symptoms that both Covid-19 and the flu share include:

  • Fever of more than 100 degrees Fahrenheit
  • Chills
  • Headache
  • Shortness of breath or difficulty breathing
  • Cough
  • Sore throat
  • Muscle pain and body aches
  • Fatigue (extreme tiredness or lack of energy) and weakness
  • Nausea or vomiting (more common in children than adults)
  • Diarrhea (more common in children than adults)

Both illnesses can result in pneumonia, and both can be asymptomatic, mild, severe, or even fatal, depending on the person. 

Differences In Symptoms

While both viruses often have similar symptoms, there are some key differences to help identify each. Specifically, the flu will usually come on suddenly and appear anywhere from 1 to 4 days after infection, while Covid symptoms can be more gradual and can develop 2 days after you’ve been infected, or not show for up to 14 days after infection. You can also look for the following differences:caucasian woman wrapped in a scarf coughing

  • Type of cough– The flu will produce a mild, dry cough, while Covid’s is also dry, but more severe, and can leave you short of breath.
  • Unique symptoms– Covid will cause unique symptoms that are not as common with the flu, including shortness of breath or difficulty breathing, runny or stuffy nose, sore throat, repeated shaking with chills, and new and sudden loss of taste or smell.

If you are wondering if you might have a common cold, the main difference between a cold and these other viruses is that a common cold will cause a phlegm or mucus-filled cough, while with Covid or the flu the cough is normally dry. 


The flu and Covid are treated differently, depending on your symptoms. There are oral antiviral medications available for the flu, but antivirals for Covid are still in the testing stages. If your illness is severe, you might need  to go to the hospital and possibly be put on a ventilator to help you breathe. 

There are vaccines available for both Covid and the flu, which can help prevent infection, or at least help lessen symptoms and usually prevent hospitalization. 

What To Do If You Experience Symptoms

If you are experiencing any of the symptoms mentioned above, there are a couple of steps that you should take, including:

  • Staying home– If you have a fever, it is important to stay home in order not to spread the virus, whether it is Covid or the flu. Even if you don’t have a fever but have other symptoms, try to refrain from going out.
  • Calling your doctor– You can call your doctor or Telehealth doctors, and notify them of your symptoms. Your doctor will write you a prescription to get tested for Covid, and schedule a testing appointment for you.
  • person with red shirt holding up covid testing kitGetting tested– If you don’t want to call your doctor,  you can schedule the testing yourself at any testing center or some drug stores. Some tests are completely free whether you have health insurance or not.
  • Seeking medical attention– If your symptoms do not go away or are severe, seek medical attention right away, whether at an urgent care or hospital.

Medicare services will cover testing and vaccinations for the flu and Covid-19 at no cost to you! These are just some of the services covered by Medicare, but it’s important to remember that not everything is covered. You will have out-of-pocket expenses, such as your Part B deductible and 20% Part B coinsurance, which can add up to a lot over the year, so it’s definitely worth looking into a Medicare Supplement Plan to save as much money as you can. Come to EZ and talk to one of our agents: we work with the top-rated companies in the nation and can compare plans in minutes for you at no cost. To get free instant quotes for plans that cover your current doctors, simply enter your zip code in the bar on the side, or to speak to a licensed agent, call 888-753-7207.

About The Author:
Cassandra Love

With over a decade of helpful content experience Cassandra has dedicated her career to making sure people have access to relevant, easy to understand, and valuable information. After realizing a huge knowledge gap Cassandra spent years researching and working with health insurance companies to create accessible guides and articles to walk anyone through every aspect of the insurance process.

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