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COVID-19 vs. flu vs. allergies

Published: July 18, 2023

Written by: Lauren Arcuri

A dandelion with seeds dispersing in the wind.

Feeling crummy? Here are six simple ways to learn more about what might be ailing you — while you seek medical care.

In this article:

Your nose is runny. Your throat is sore. You feel a little draggy. Is it allergies? After all, pollen seasons in the United States and Canada last longer and feature more pollen than they have in decades past. But then your coworker just called in sick — maybe it’s the flu? Of course, it could always be COVID-19, right?

: Left: A thermometer, mask, bed and pills for treating COVID-19. Right: Illustration of a young woman shopping in the cold & flu aisle and an older woman shopping in the allergies aisle.

What all these conditions have in common

If you’re having symptoms like these, there’s a good reason you might be confused and a little bit worried. “The fact is that there’s a lot of crossover in common symptoms among these conditions,” says John James, MD, a board-certified allergist and spokesperson for the Asthma and Allergy Foundation of America (AAFA). And with medical news breaking all the time, it often seems tough to keep track of, sort out and interpret symptoms.

If you’re feeling unwell, remember that you could be putting others at risk, so it’s important to get tested for COVID-19, especially if you’re experiencing loss of taste or smell. At-home tests, like the CVS Health At Home COVID-19 Test KitFlowFlex COVID-19 Antigen Home Test and BinaxNOW COVID-19 Antigen Self Test, are available over the counter. If you test positive, consult with your primary care physician and stay home for the recommended number of days while you recover to avoid infecting others.

Meanwhile, it can be reassuring to arm yourself with knowledge about some important differences in the ways you might experience these conditions. Ask yourself these questions:

How long have you had symptoms?

“The longer your symptoms have lingered, the more likely it is that it’s allergies,” says Mitchell Grayson, MD, chair of AAFA’s Medical Scientific Council. “Compared to flu or COVID-19, seasonal allergies typically last longer — for several weeks.”

  • Allergies: usually 2 to 3 weeks per allergen
  • Flu: anywhere from 1 to 14 days
  • COVID-19: anywhere from 2 to 25 days (except in the case of long COVID)

Was the onset sudden or gradual?

You know the feeling — one minute you’re fine, and the next you’re holding your head in your hands. If the onset was sudden, it’s more likely to be allergies or the flu — although, in some cases, COVID-19 symptoms can come on rapidly too.

  • Allergies: abrupt
  • Flu: abrupt
  • COVID-19: rapid or more gradual

Are you sneezing or itchy?

Itching, usually in the nose, mouth, eyes or throat, is a telltale sign of allergen triggers like pollen — and a good indicator you have allergies rather than COVID-19 or the flu. Sneezing is most common in allergies, although it also can happen in other illnesses. CVS Health Allergy Relief Non-Drowsy Fexofenadine TabletsZyrtec 24 Hour Allergy Relief Tablets and Flonase Non-Drowsy Allergy Medicine can all help relieve these symptoms.

  • Allergies: common
  • Flu: sometimes sneezing but not itchy eyes
  • COVID-19: rare

Do you have a cough?

If you have a bad cough, it’s probably not allergies. For relief from a cough, try Vicks DayQuil & NyQuil Cough, Cold & Flu Relief Combo or Mucinex DM 12 Hr Max Strength Expectorant & Cough Suppressant Tablets. These medicines may also help with an accompanying sore throat.

  • Allergies: dry cough is possible
  • Flu: common
  • COVID-19: common

Do you have fever, weakness, or aches and pains?

Allergies can sometimes make you feel tired but generally don’t cause widespread body aches or fever the way COVID-19 or the flu can. If you’re feeling warm, check with an at-home thermometer like the CVS Health Rigid Tip Digital Thermometer to see if you’ve developed a fever.

  • Allergies: uncommon
  • Flu: common
  • COVID-19: common

Do you have diarrhea, nausea or vomiting?

These gastrointestinal symptoms might indicate COVID-19 or the flu. They’re not typically part of seasonal allergies.

  • Allergies: not common
  • Flu: sometimes
  • COVID-19: common

What about the common cold vs. COVID-19 (and everything else)?

Nearly identical symptoms can leave people who are feeling under the weather wondering if they could be down for the count with a cold or COVID-19. Adults suffer from an average of two to three colds every year, according to the Centers for Disease Control and Prevention. Sneezing, a stuffy or runny nose, a sore throat, coughing and watery eyes are common symptoms, some of which can last for 10 to 14 days. COVID-19 symptoms can be similar, although the cough that accompanies COVID-19 is typically dry. It’s also rare for colds to cause gastrointestinal distress and headaches, and they usually don’t cause fatigue and weakness. When in doubt, it’s always a good idea to take a COVID-19 test and seek medical care.

This content is for informational purposes only and is not medical advice. Consult with your health care provider before taking any vitamins or supplements, and prior to beginning or changing any health care practices.