How to Tell the Difference Between COVID-19 and Flu

Flu season peaks between December and February. Paired with the ongoing battle with COVID-19, medical experts from NewYork-Presbyterian medical groups say we could have a “twindemic” on our hands — an influenza epidemic unfolding in the middle of a relentless COVID-19 pandemic.

The 2019 influenza virus caused an estimated 35 million illnesses in the U.S. The severity of this year’s flu season is unpredictable, but a lot of people may be coughing and sneezing, so the likelihood of transmission is much higher when you’re having active symptoms.

But what exactly are those symptoms? Just as in the spring when it was difficult to tell the difference between seasonal allergies and COVID-19, the challenge now will be identifying what could be signs of COVID-19 vs. flu.

COVID-19 vs. Flu: What’s the Difference?

Medical experts say that it may be very hard to tell the difference between influenza and COVID. Therefore, although we outline the differences below, it is recommended to call your doctor to ensure the diagnosis and that you take the proper steps.

Even though the flu and COVID-19 are caused by two totally different viruses, they share a number of symptoms:

There are, however, two distinct differences between the flu and the coronavirus that causes COVID-19.

covid-19 vs flu

First, the loss of taste and smell is specific to COVID-19 and is not seen in people who have the flu. While it does not happen in all patients, this is a very important difference that can help distinguish between symptoms of flu and COVID-19 (about 38% to 55% of patients have reported loss of taste and around 40% have reported loss of smell). This specific symptom might come on anywhere from two days after contracting the virus to up to 14 days after symptom onset.

Second, the way in which symptoms present themselves in patients is very different. Both the flu and COVID-19 cause a cough and shortness of breath, but overall, COVID-19 symptoms tend to last longer than the flu. Medical experts say COVID-19 symptoms may last for several weeks if not months.
Shortness of breath can also come later with COVID-19 and becomes more severe and long-lasting than the flu.

There are also some new and ongoing reports of symptoms associated with COVID-19 that people should be on the lookout for:

Red, swollen eyes. There have been occasional reports of red, swollen, and itchy eyes in some COVID-19 patients, which can look like conjunctivitis (or pink eye). This is a symptom that can come on with other strains of coronavirus, so while not a distinguishing factor for COVID-19 specifically, it’s something to be watchful for.

Skin rashes. Viruses are often associated with rashes, so it’s not unusual for you or your child to develop one. Mostly reported in younger people, early data suggests that different skin conditions may coincide with COVID-19. These may range from little red bumps and hives to chilblains — now temporarily called ‘COVID toes’ — which are painful, red-purple, or itchy bumps on the toes.

If you or your child has any new skin condition or rash, call your doctor just to be safe. Since it can be hard for a clinician to distinguish whether a skin rash is from a COVID-19 infection or, say, hand, foot, and mouth disease (a viral infection that manifests as painful mouth sores and blisters on the palms of the hands and soles of the feet), your doctor will likely want to test you or your child for COVID-19.

How to Tell the Difference Between COVID-19 vs. Flu in Children

Reports have shown that COVID-19 is less severe in children than it is in adults. It’s also rare, making up about 1% to 2% of COVID-19 cases worldwide. That being said, multisystem inflammatory syndrome in children (MIS-C), while rare, is a condition associated with COVID-19 and can occur in children ranging from toddlers to teens.  Lookout for symptoms, including fever, vomiting, lethargy, and abdominal pain. If your child is experiencing common flu symptoms coupled with any of the above symptoms, contact their pediatrician.

What to Do if You Think You Have the Flu, COVID-19 — or Both

Yes, it’s possible to test positive for influenza and COVID-19 at the same time, but experts say the chances of having a coinfection are very, very low. If you find yourself experiencing any of the symptoms discussed in this article, here’s a game plan for how to quickly determine a diagnosis.

  • Talk to your doctor. If you’re coming down with a telltale sign of COVID-19 or the flu, seek medical care. Experts say it’s a good idea to put on a mask and self-isolate from your family if you have symptoms, to play it safe.  
  • Get tested. Experts agree that it’s important to be tested as quickly as possible for COVID-19 and flu. Here’s some good news: The nose swab can be used to test for both COVID-19 and the flu. Schedule an appointment with your doctor or local health clinic, or visit an urgent care center where tests should be available.
  • Start treatment. After a diagnosis, move forward with the appropriate treatment. For the flu, the gold standard is an antiviral drug that your doctor might prescribe which helps to lessen the severity of symptoms and shorten duration of the illness. For milder cases of COVID-19, most people can recover at home by monitoring their symptoms, resting, and drinking fluids.

If you are having trouble breathing, persistent pain, chest pressure, new confusion, an inability to wake or stay awake, or bluish lips or face, seek emergency medical care immediately.

How to Protect Yourself Against the Flu and COVID-19

To avoid a potential “twindemic” this year, medical experts at NewYork-Presbyterian medical groups recommend taking the following precautions:

If there was ever a year when you were going to get a flu shot, this is the year. Call your doctor to make an appointment.

  • Practice safety precautions. Fortunately, the preventive measures for COVID-19 also apply for the flu: avoiding large crowds and gatherings, wearing a mask, social distancing, frequent handwashing, and staying at home when you feel sick.
  • Take care of your immune system. Caring for your immune system is very important to fight off infections, especially viruses. Boost your immunity by eating a healthy, balanced diet, exercising regularly, and getting enough sleep.

For more articles about science, care, and wellness, visit healthmatters.nyp.org.