Flu, Cold or COVID? A Simple Guide to Symptoms

Woman holding a tissue against a blue background, wondering she she has the flu, a cold, or COVID.

Dealing with the sniffles or lingering cough is annoying at the best of times. During a global pandemic, brought on by a respiratory illness with flu-like symptoms? Downright stressful. 

And the tricky thing about identifying COVID-19 is that it presents a really wide range of symptoms. Some cases involve no symptoms whatsoever, mild cases may only mean a cough or runny nose, moderate cases can feel a lot like the flu, and severe cases can require hospitalization. Usually, you’ll need to take a test to know for sure if you’ve been infected.

While it’s important to take any possibility of COVID-19 seriously to avoid spreading the virus, we don’t want you to panic. If you (or a loved one) are feeling unwell, the best approach—as always—is to take a calming breath and start with the science. 

In this post, we’ll go over the usual symptoms, timing, and recommended next steps for the three likely culprits: the common cold, the flu, and COVID-19. 

The symptom unique to COVID-19

Let’s get this one out of the way. The CDC reports that there’s really only one symptom that’s mostly specific to COVID-19, compared to the common cold and flu: losing your sense of smell or taste

“There are many symptoms of a ‘common cold,’ flu and COVID-19 that overlap, including fever, sneezing, cough and fatigue,” epidemiologist Dr. Sadiya Khan recently told Northwestern University. “One symptom that seems to be unique to COVID-19 is a loss of sense of smell or taste. However, none of these symptoms are perfect to diagnose the cause of ‘cold-like’ symptoms, and the only way to know for sure is to get tested.”

If you can’t detect strong aromas like coffee or garlic, and you’re experiencing a fever and/or a persistent cough, stay home, isolate yourself, and set up a video visit at zoomcare.com to get safe and easy testing. 

Shared symptoms for the flu and COVID-19

While COVID-19 is difficult to identify from symptoms alone, it’s usually easier to tell a cold from the flu, because colds don’t tend to involve severe body aches or fever. If you’re running a fever or feeling that familiar “I got hit by a truck” fatigue, it’s likely the flu or COVID-19. (Sorry.) 

That said, the following symptoms are common for all three viruses:

  • Cough (usually milder with the cold, usually deep or dry with COVID-19)
  • Shortness of breath
  • Sore throat (more common in the cold than the flu or COVID)
  • Runny or stuffy nose (more common with the cold, rarely the only symptom for the flu)

Symptoms that often or sometimes appear in both COVID-19 and the flu, but rarely with a cold, include:

  • Fever (or feeling feverish, like the chills)
  • Fatigue or weakness
  • Muscle pain or body aches
  • Headache 
  • Vomiting, nausea, and diarrhea (more common in children than adults, and more common with the flu than COVID-19)

Note that many mild cases of COVID-19 only involve a runny nose or congestion—no fever ever appears. So don’t assume you just have a cold if a sniffle or stuffy nose is your only symptom. You could still be infected with COVID-19, and run the risk of getting others seriously ill.

Common symptoms of the common cold

The good news: sneezing, watery eyes, and post-nasal drip are usually symptoms of a cold or allergies. Sometimes, they’ll appear with the flu. They’re even less common with COVID-19, but not impossible, because COVID can display a wide range of symptoms and we’re still learning about this new virus.

Timing of symptoms 

Don’t just pay attention to what symptoms you experience—notice when you start to feel unwell, how quickly they appear after possible exposure, and how long they last.

  • Cold symptoms usually show up within 2 to 3 days of infection, and they tend to appear gradually. 
  • Flu symptoms usually begin about 1 to 4 days after you’ve been infected by the virus, and tend to show up suddenly.
  • COVID-19 symptoms, if they appear at all, typically show up 5 to 7 days after exposure—but can begin as early as 2 days or as late as 14. 

Symptoms for all three viruses can last for a few weeks, but cold and flu symptoms usually get better over time. If your symptoms continue to worsen after a week, go to zoomcare.com to schedule a remote COVID-19 screening. 

What to do if you show symptoms of COVID-19

If you show any of the above symptoms of COVID-19, you should schedule a COVID screening  right away. If you know you’ve been exposed to COVID-19 by being in close contact (defined as 15 minutes or more within a 24-hour period) with someone who tests positive, even if you have zero symptoms, you should isolate yourself and call your doctor. 

Red flags for COVID-19

We’ve focused mostly on common and mild symptoms, but if you or a loved one experiences any of the following, seek emergency medical care immediately:

  • Trouble breathing or gasping for air
  • Blue or purple lips or face
  • Persistent chest pain or pressure 
  • New confusion
  • Inability to stay awake or conscious 

Bottom line: play it safe, but don’t panic

We know for sure that COVID-19 is very contagious and we don’t yet have a vaccine. Testing can help you know for sure if you have the virus, but false negatives are frequent, so play it safe. If you show any symptoms, wear a mask at all times, avoid unnecessary contact with others (even in your household), wash your hands frequently, and call your doctor to discuss your specific symptoms and circumstances. 

Finally, don’t panic. Your sniffles are statistically unlikely to land you in the hospital, but heightened stress levels can take a toll. That’s why we’re here to help you deal with COVID-19 concerns of all kinds, whenever you need us.