Common symptoms: allergies vs. flu vs. COVID-19

In this article:

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^® brand at-home COVID-19 test kit, FlowFlex COVID-19 antigen home test and BinaxNOW COVID-19 antigen self test, are available over the counter. If you test positive, consult your health care provider and follow current isolation recommendations 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:

This table summarizes and compares the common symptoms of allergies, the flu and COVID-19. Your symptoms may vary. Speak with your healthcare provider if you are feeling unwell.

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 Asthma and Allergy Foundation of America’s (AAFA) 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: symptoms may last anywhere from 1 to 4 days after infection
• COVID-19: symptoms can last anywhere from 2 to 5 days and even up to 14 days after infection (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 eyes, mouth, nose 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^® brand allergy relief support nondrowsy fexofenadine tablets, Zyrtec 24 hour allergy relief support tablets and Flonase nondrowsy allergy relief support medicine can all help relieve these symptoms when caused by allergies.

• 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 support from a cough, try Vicks DayQuil and NyQuil cough, cold and flu relief support combo or Mucinex DM 12 hour maximum-strength expectorant and cough suppressant tablets.

• 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^® brand 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 (CDC). A sore throat, a stuffy or runny nose, coughing, sneezing 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 may not 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 your health care provider before taking any vitamins or supplements and prior to beginning or changing any health care practices.