Once upon a time, a scratchy throat and runny nose meant the onset of a cold or the flu. That was before the pandemic. Today, the highly contagious BA.5 and BA.4 versions of omicron are causing COVID-19 symptoms that closely resemble those of cold and flu, leading many people to wonder: What kind of infection do I have?

“It’s much harder to tell the symptoms of cold, flu, and COVID-19 apart now than it was at the beginning of the pandemic,” says Sharon Nachman, MD, chief of the division of pediatric infectious diseases at Stony Brook’s Renaissance School of Medicine in New York. With all three illnesses, “there tend to be upper respiratory symptoms. So thinking that you can be super specific in diagnosing yourself, as in, ‘I have laryngitis, so I must not have COVID-19,’ isn’t realistic,” Dr. Nachman says.

To complicate matters, most people who get COVID-19 these days, particularly those who are vaccinated and boosted, are likely to have mild symptoms, or even no symptoms at all. “People may have a sniffle or two in the morning and be fine after that,” says Nachman.

Testing May Be the Only Way to Diagnose Your Infection

If you’ve got some kind of respiratory bug but don’t know what it is, doctors have one piece of advice: Get tested.

Given the similarities between COVID-19, the flu, and the common cold, “If we don’t test people, we’re merely guessing at things,” says Jeffrey Loria, MD, an internist in New York City. “If someone reaches out with fever or any respiratory symptoms, I’d make sure to get them tested for both the flu and COVID.”

The benefit to testing for COVID-19 is obvious by now: By going into quarantine as soon as possible, you minimize the chance of spreading the virus to others. (The current CDC recommendation is five days of isolation following the first symptoms or a positive test, followed by five days of wearing a mask around others.)

“The sooner you take a test, the sooner you’ll be on the path to doing the right thing for the people around you,” says Priya Nori, MD, an infectious diseases specialist at Montefiore Health System in New York City.

Learning whether you have COVID-19 or the flu as soon as possible can also help you determine a course of treatment. If a test reveals you have COVID-19, for instance, you have five days from the onset of symptoms during which you can begin taking the antiviral drug Paxlovid (nirmatrelvir with ritonavir), if eligible.

“With Paxlovid, we now have a great oral medication to treat COVID-19. It prevents disease progression and hospitalization, so that’s a win,” says Nachman. Indeed, a study published in February 2022 in The New England Journal of Medicine found that people who took Paxlovid had an 89 percent reduction in hospitalization and death.

If You Have Flu, You Need to Know It

While COVID-19 has been top of mind for the past few years, the flu also has the potential to make you very ill and lead to potentially serious complications. As with COVID-19, it’s important to get a diagnosis and isolate yourself as soon as possible to avoid infecting others.

Experts are concerned that there might be a lot more flu going around during the 2022–2023 season than in the past few years due to the lifting of most COVID-19 safety protocols. “Because of masking, social distancing, and people staying home from school and work in 2020 and even 2021, there was a relative paucity of influenza,” says Dr. Loria. “But this year, I’m predicting we’ll see a more robust return of flu, given that fewer people are masking, travel is up, kids are back in school, and more people are heading into the office.”

If a test shows that you have the flu, you might consider getting a prescription for the antiviral drug Tamiflu (oseltamivir) to shorten the length of time you’re sick. Doctors generally recommend you begin taking this medication within 48 hours of developing symptoms, so time is of the essence.

It has always been important to get a yearly flu vaccine, and this continues to be true, particularly if you want to avoid a double whammy of flu plus COVID-19. Though the vaccine isn’t 100 percent effective at preventing the flu, it is very safe and reliable. And if you get the vaccine yet do end up with the flu, you will likely have a much milder case.

Top Cold Symptoms

Looking at the top symptoms of cold, flu, and COVID-19 reveals many areas of overlap, plus a few potential distinctions.

“We’ve all had colds, so we tend to know what the symptoms are,” says Loria. They’re typically less severe than those of the flu, he adds, but may be indistinguishable from symptoms caused by the lastest omicron variants, including:

Runny or stuffy nose
Mild cough
Sore throat
Malaise
Muscle or body aches
Headache

Top Flu Symptoms

“Flu symptoms are apt to come on very abruptly, versus symptoms of COVID-19 or a cold,” says Loria. These symptoms can include:

A high fever lasting several days (“Fever in the flu tends to be higher than with COVID-19,” says Loria.)
Chills
Malaise (fatigue)
Muscle or body aches
Dry cough (“Often with the flu you get a dry ‘barking’ cough, which is not something you see with a cold,” says Loria.)
Headache
Runny or stuffy nose
Sore throat
Sometimes, diarrhea and vomiting (more common in children than adults)

Unlike COVID-19, the flu is seasonal, mainly occurring in fall and winter. ”We know it’s coming every year,” says Dr. Nori.

Top COVID-19 Symptoms

COVID-19 can bring on the same symptoms as a cold and the flu:

Sore throat
Runny or stuffy nose
Headache
Muscle or body aches
Chills
Fever (typically low-grade)
Cough
Malaise
Vomiting, nausea, diarrhea

COVID-19 Safety Measures Can Prevent Cold and Flu, Too

Tactics meant to prevent the spread of COVID-19 can also reduce transmission of colds and the flu. Staying home if you feel ill and frequent handwashing can help keep you healthy during cold and flu season.

Getting vaccinated for both the flu and COVID-19 (if you haven’t done it already) and getting the bivalent omicron booster is essential.

And wearing a mask is still an easy and effective way to ward off all kinds of germs — and not infect the people around you. “The idea that masking is just for someone who has COVID is not the best way to think about it,” says Nachman. “No one wants to be coughed or sneezed on. The point is for all of us to protect each other.”