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Sure Signs You've Already Had COVID, Say Experts

Knowing these signs can save your life.

COVID is sneaky. One of the first and biggest challenges for experts trying to get a handle on the virus was that many infected people had no symptoms, or vague ones. That hasn't changed. You might contract COVID and not realize it at all, or you might not realize it until long-term symptoms appear. There are some signs of COVID that have been commonly reported and may be easily confused for other illnesses or physical issues. They deserve a spot on your radar—and a call to your doctor if they surface. Read on to find out more—and to ensure your health and the health of others, don't miss these Sure Signs You Have "Long" COVID and May Not Even Know It.


Chronic Fatigue

Woman sleeping on the couch in the living room.

Fatigue is one of the most commonly reported symptoms of COVID infection—and an almost universal sign of "long COVID." (In one survey of long-term COVID symptoms, fatigue was reported by 100% of respondents.) If you're experiencing fatigue that lingers and isn't abated by rest, it's a good idea to visit your doctor to determine the cause, whatever it may be.


Headaches That Won't End

Young woman with headache

If you're not headache-prone, a constantly aching noggin could be a sign of COVID. Researchers with the COVID Symptom Study are tracking new COVID cases in people who are unvaccinated, fully vaccinated and partially vaccinated. They found that headache was the #1 symptom reported among all three groups.  



Woman blowing her nose into tissue

Likewise, if you're not prone to seasonal allergies, and you find that you've been sneezing a lot, it could be COVID. The COVID Symptom Study has found that cold symptoms like a runny nose and sneezing—both of which were not considered indicators of COVID earlier in the pandemic—are increasingly common. "If you've been vaccinated and start sneezing a lot without an explanation, you should get a COVID test, especially if you are living or working around people who are at greater risk from the disease," the researchers said.

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Loss of Taste or Smell

tasting food

Last winter, a study at the University of Washington found that 30% of people who've had COVID experience persistent symptoms for as long as nine months after their initial illness. That study found that the five most common lingering symptoms were fatigue, loss of smell or taste, headache, trouble breathing, and muscle or body aches. 

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Brain Fog

Woman hands on his head felling headache dizzy sense of spinning dizziness with motion

Many people with COVID report experiencing confusion or the ability to concentrate, a.k.a. "brain fog," which can linger for weeks or months after their initial infection. Last August, a study published in the Lancet found than 55% of people diagnosed with coronavirus reported neurological symptoms three months after their diagnosis. 

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How to Stay Healthy 

Nurse with face mask sitting at home with senior woman and injecting covid 19 vaccine.

Just because you may have had COVID doesn't mean you're immune to the Delta variant. Follow public health guidelines and help end this pandemic, no matter where you live. Get vaccinated ASAP. If you live in an area with low vaccination rates, wear a face mask that fits snugly and is double layered. Don't travel. Practice social distancing, avoid large crowds, practice good hand hygiene, and to protect your life and the lives of others, don't visit any of these 35 Places You're Most Likely to Catch COVID.

Michael Martin
Michael Martin is a New York City-based writer and editor whose health and lifestyle content has also been published on Beachbody and Openfit. A contributing writer for Eat This, Not That!, he has also been published in New York, Architectural Digest, Interview, and many others. Read more about Michael