BHealthy Blog

How to Tell the Difference Between COVID-19, the Flu, Allergies & a Cold

Updated on October 13, 2021

Dr. Erica Stokes, Baptist Health Family Clinic-Otter Creek

During this time of year, more and more people are starting to feel symptoms of fall allergies, cold, flu, and of course, COVID-19. Unfortunately, all of these illnesses can have similar symptoms, including cough, fatigue, headaches, runny nose, sore throat and more. 

If you start to experience any of these symptoms, the big question ishow do you know which illness you have?

Symptom Overlap – Which Symptoms Correspond to Which Illnesses?

It can be tricky to tell because there is so much overlap. A lot of times, you may have some congestion or sore throat, and those symptoms do overlap. However, we tend to see fever more commonly with flu, and it tends to be sudden onset. You may feel as though it hits you out of the blue. With COVID-19, fever may be a little slower to onset. 

For seasonal allergies, you may be accustomed to experiencing those same symptoms around this time of year, and it can follow that same pattern you’re used to.

Ultimately, it can be challenging to tell the difference from symptoms alone. For a more in-depth look at typical symptoms by ailment, the following chart breaks it down.


Symptoms begin within 14 days of exposure.

Length of symptoms varies, but often 10 days or more.

Symptoms begin abruptly.

Symptoms last 5-7 days.

Symptoms begin gradually.

Symptoms last 3-10 days.

Symptoms begin gradually.

Symptoms are seasonal.

Body achesSometimesYesYesNo
ChillsSometimesYesLess CommonNo
Dry CoughYesYesSometimesYes
Exposure to germsYesYesYesNo



FeverYesYesLess CommonNo
Itchy eyesNoNoNoYes
Nasal Congestion/ Runny NoseLess CommonYesYesYes



SometimesLess CommonLess CommonLess Common
Sore throatSometimesSometimesYesSometimes
Shortness of breathYesYesLess CommonSometimes
Loss of taste or smellYesSometimesSometimesLess Common

Infection Overlap – Can I Have More Than One at the Same Time?

It is actually possible to have the flu or other illnesses and COVID-19 together, and a lot of people may not have even thought of that. That’s one reason why it’s so important, even if you have not gotten the flu shot in the past, to go ahead and get one this season. 

It’s time now because that is one way we can try to protect patients from getting at least the flu. Learn more about the importance of getting your flu shot, where to get a flu shot & more.

Where DON’T the Symptoms Overlap?

There do seem to be a couple of things that are not associated with each other or are not overlapping. We’re finding that a pretty telltale sign for COVID-19 is a sudden loss of taste or smell. You should get tested to make sure, but that is something that seems to be unique to COVID-19.

Another thing we’ve noticed is more diarrhea and stomach upset with COVID-19, and sometimes severe shortness of breath. If you are experiencing severe shortness of breath or chest pain, please visit your nearest emergency room.

To learn more about COVID-19, including testing sites and information, frequently asked questions & more, visit our COVID-19 resource library.