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This is Typically the First Sign You Have COVID

It's easy to dismiss. But it's the #1 sign of coronavirus, this study says.
FACT CHECKED BY Checkmark Alek Korab
Woman experiencing a bad headache

At this point, you probably know about the early symptoms of COVID to be alert for: Dry cough, fever, shortness of breath, loss of taste or smell. But COVID-19 can cause a wide spectrum of symptoms, some of which can be mistaken for minor illnesses or the stresses of everyday life. And one study has found that the most common first sign of COVID can be particularly hard to isolate. Read on—and to ensure your health and the health of others, don't miss these Sure Signs You've Already Had Coronavirus.

The Most Common Sign of COVID is Fatigue

According to the COVID Symptom Study—a UK-based study that encourages participants to regularly log their COVID status and symptoms in an app—the most common early sign of COVID-19 is fatigue. According to researchers, 82% of people diagnosed with coronavirus experienced fatigue within the first seven days of their illness. In second place: 72% reported a headache.

While many people might believe that fever is the most reliable early indicator of COVID—supported by the widespread institution of temperature checks outside various businesses and public spaces—the data from the COVID Symptom Study, along with other studies, doesn't bear this out. "Forty percent of all age groups reported having a fever in the first seven days," the researchers wrote.

However, they noted: "This or loss of smell and persistent cough are still the key symptoms to be aware of—so people with the classic three symptoms of persistent cough, fever or loss of smell should certainly seek a COVID test."

RELATED: COVID Symptoms Usually Appear in This Order, Study Finds

Fatigue not always a COVID sign

The COVID Symptom Study assembled its data from app users who had tested positive for COVID-19 through a swab test and reported the symptoms they experienced through the first week of their illness. 

The Centers for Disease Control & Prevention lists fatigue as a common early sign of COVID-19. But fatigue is common to any viral infection—it happens as the body attempts to fight off an illness—and it doesn't automatically indicate that you've been infected with coronavirus. 

If you're feeling run-down to the point that it's bothersome, and it doesn't have a clear explanation—as in, like most of us, you haven't run a marathon lately—the best thing to do is to contact your healthcare provider, explain your symptoms and concerns, and follow their advice about how to proceed, including any potential COVID testing or treatment.

RELATED: If You Feel This, You May Have Already Had COVID, Says Dr. Fauci

How to survive this pandemic

As for yourself, do everything you can to prevent getting—and spreading—COVID-19 in the first place: Wear a face mask, get tested if you think you have coronavirus, avoid crowds (and bars, and house parties), practice social distancing, only run essential errands, wash your hands regularly, disinfect frequently touched surfaces, and to get through this pandemic at your healthiest, don't miss these 35 Places You're Most Likely to Catch COVID.