Is It a Cold, the Flu, or COVID-19?
While symptoms of all three infections overlap, there are crucial differences and steps you can take to protect yourself.
Before the pandemic, a scratchy throat and stuffy nose were nothing to get alarmed about. Most of us experiencing these symptoms could assume we had a cold and power through.
In the era of COVID-19, however, these symptoms can bring on a whole new level of anxiety. “There’s a tremendous amount of overlap between symptoms of a cold, the flu, and COVID-19,” says Jeffrey Loria, MD, an internist in New York City.
“It’s not that you have to panic,” he adds. “If you get a simple runny nose or scratchy throat without a fever or other significant respiratory symptoms, it’s likely that you’ve just got a cold.”
But that’s not always the case now that the novel coronavirus has become a part of our lives. “COVID can present as a common cold, with a runny nose, congestion, and a headache,” says Natasha Chida, MD, an infectious diseases physician at The Johns Hopkins Hospital in Baltimore.
“In fact, 80 percent of people who get COVID-19 develop mild symptoms that resemble those of a cold,” she adds.
COVID-19 symptoms can also mimic signs of the flu, which is especially concerning as flu season approaches and distinguishing between the two illnesses becomes vital.
While the flu barely made an appearance last year, thanks to COVID-19 precautions like mandatory masking and social distancing, doctors are anticipating a significant uptick in flu cases this fall and winter as people return to offices and classrooms.
“The flu usually hits with a fever, muscle aches, and a feeling of being rundown, all of which can be present in COVID-19,” Dr. Chida says.
If you begin to feel unwell and don’t know why, the most important thing you can do — in addition to staying home and isolating yourself — is call your healthcare provider to describe your symptoms. “Talking to your physician about your symptoms and whether to get tested is the best first step,” says Chida.
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Top Cold Symptoms
“We’ve all had colds, so we tend to know what the symptoms are — and they are typically less severe than those of COVID-19 or the flu,” says Dr. Loria.
Cold symptoms can include:
- A runny nose
- Mild cough
- Sore throat
- Body aches
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 — “One of the hallmarks of the flu is a higher fever than you’d get with COVID-19, which generally tends to be in the 100.5 [degrees F] range,” Loria says.
- Malaise, fatigue, and weakness
- Muscle aches
- Dry cough — “Often with the flu you get a dry ‘barking’ cough, which is not something you see with a cold, though you may see it with COVID-19,” says Loria.
Unlike COVID-19, the flu is seasonal, mainly occurring in fall and winter. ”We know it’s coming every year,” says Priya Nori, MD, an infectious diseases specialist at Montefiore Health System in New York City. As for COVID-19, she says, “you can get it in warm weather or cold, in spring, summer, winter, and fall.”
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Top COVID-19 Symptoms
COVID-19 can bring on the same symptoms as a cold (congestion, headache, body aches, sore throat) and the flu (fever, cough, overall malaise, and muscles aches).
“But there are also outside-the-box symptoms that you may not see with the common cold or flu,” says Dr. Nori.
COVID-19 symptoms include:
- A lack of ability to smell or taste, particularly at the onset, when there are no other symptoms present
- Diarrhea — “We generally don’t think of diarrhea and other gastrointestinal symptoms as something that occurs with influenza in adults,” says Nori. “But with COVID, diarrhea can occasionally be the only symptom, along with profound fatigue.”
- Nausea or vomiting
- Shortness of breath, difficulty breathing, or chest tightness
- Rash — “Young children with COVID may get a rash on their fingers and toes,” says Nori. “And, rarely, we’ve seen something called multisystem inflammatory disorder in children [multisystem inflammatory syndrome in children, or MIS-C], which is similar to Kawasaki disease, and is not something we see with the flu.”
- Chest pain or heaviness in the chest
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Getting a Diagnosis
The overlap in symptoms between the cold, the flu, and COVID-19 means that the only way to diagnose the illness is testing.
“If we don’t test people, we’re merely guessing at things,” Loria says. “If someone reaches out with fever or any respiratory symptoms, I’d make sure to get them tested for both the flu and COVID.”
Loria adds, “[In the past], if a patient had flu-like symptoms, I’d be likely to give them Tamiflu [a flu medication] without testing. But [now] those symptoms could be COVID. That’s why trying to get people tested for both COVID-19 and the flu is our number one recommendation.”
The benefit to testing for COVID-19 is obvious by now: If you are found to be infected with the novel coronavirus, “the sooner you take yourself out of circulation and isolate yourself, the sooner you’ll be on the path to doing the right thing for the people around you,” says Nori.
There are also more treatments available for COVID-19 than in the beginning of the pandemic, she adds.
Monoclonal antibody drugs, for instance, can help people with mild or moderate symptoms who are at high risk of progressing to severe COVID-19 because of their age (65 and over) or underlying medical conditions. For treatment to be effective, however, it must begin early — within 10 days of the onset of symptoms.
For the small percentage of people who end up requiring hospitalization for COVID-19, remdesivir, “if given early enough, can act to block the virus from entering immune cells and the respiratory tract, and shorten the time to recovery,” Nori adds.
A Flu Shot Is Vital
It has always been important to get a yearly flu vaccine, “but it’s absolutely critical to get a flu shot this season,” emphasizes Chida.
Last winter’s lack of flu may have set us up for a particularly early, and potentially severe, flu season, says the Centers for Disease Control and Prevention (CDC). The agency is urging virtually everyone over age 6 months to get a flu shot, ideally by the end of October.
Though the vaccine isn’t 100 percent effective, it is very safe and reliable. And if you get the vaccine yet do get the flu, you will likely end up with a much milder case.
There are reasons beyond your own health to get a flu shot ASAP. “You’ll be protecting your community,” says Chida. As delta or other new coronavirus variants continue to circulate, “we don’t want the health system to be overwhelmed with both COVID and the flu,” she adds.
Plus, you want to avoid getting the flu and COVID-19 at the same time. “Whenever you get a viral infection, it weakens your immune system, so it’s best to take steps so that doesn’t happen,” says Chida.
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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. “Masks work amazingly well,” says Nori. “They’re a low-budget, low-stakes intervention with a high-stakes reward.”
Social distancing, staying home if you feel ill, and frequent handwashing are also key.
Getting vaccinated for both the flu and COVID-19 (including getting a COVID-19 booster if you qualify), plus taking all these other safety measures, can help keep people healthy — and sniffle-free — this fall and winter.