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Signs You've Already Had COVID, According to the Mayo Clinic 

What experts know about Long COVID so far. 
FACT CHECKED BY Emilia Paluszek

Although COVID cases are declining, the effects of the virus are here to stay. Millions of people are experiencing symptoms that can last for weeks or months even though they're no longer positive for COVID. "Long Covid in the US is defined as symptoms from COVID infection for 4 weeks after your recovery. Europe defines long COVID as being symptomatic 3 months from COVID infection and it can include symptoms such as fatigue, exertional fatigue, brain fog, and difficulty with memory recall are the top symptoms," Dr. Anthony Harris, a COVID-19 expert with HFit Health tells Eat This, Not That! Health. According to Penn State College of Medicine, more than half of the 236 million people diagnosed with COVID-19 since December 2019 will experience post-COVID symptoms up to six months after recovering and the Mayo Clinic reveals anyone can have Long COVID. While researchers are still learning about long haulers, Dr. Harris explains what the medical community knows so far and what symptoms to watch out for. Read on—and to ensure your health and the health of others, don't miss these Sure Signs You've Already Had COVID.


Common Long COVID Symptoms

Woman recovering from an illness in bed at home.

The Mayo Clinic lists Long COVID symptoms. Dr. Harris took a look and walked us through each one:

Fatigue. low energy, not having enough energy to be functional. You can't function to do your normal daily activities at work or at home. That experience can be different for everyone.

Exertional Fatigue. This has to do more with a decrease in your endurance. If you used to be able to walk from your office to your lunch venue, or from home to the park, your ability to do that's now decreased. After a period of exertion having a period of fatigue for a prolonged period of time.

Brain Fog. Likely caused by inflammatory cells not normally present in the brain, vascular causes difficulty with name recall and complex thoughts that may persist for months on end.

Persistent Cough. If prior to COVID you didn't have a persistent cough and now do or if you have a severe cough or one that has lingered or you have a cough that is disruptive. Especially today, coughing in public has become much more noticeable as a sign of illness being a common symptom to COVID.

Chest Pain. Usually not indication of some underlying cardiogenic effect but more so chest pain because of the impact on the respiratory system

Trouble Speaking. This is oftentimes associated with brain fog

Muscle Ache. Disruptive to your day and can be quite impairing and has been documented to be a source of disability with people with long COVID."


Long COVID Side Effects

Sad man sitting on a bed, girlfriend in the background.

Dr. Harris says, "There are still effects from COVID that we know affect individuals like erectile dysfunction and cardiogenic effects and we'll see an escalation in diagnoses from long COVID as we understand how it affects organs and the vascular system which is why we still want to communicate to people to get vaccinated to decrease infection, decrease transmission, decrease severity, and decrease Long COVID. This includes practicing safe measures to protect yourself and others."


What Causes Long COVID?

Radiologist looking at the MRI scan images.

Dr. Harris shares, "As we understand it today, it is likely caused by clinical effects of the virus affecting the blood vessels and organs, the brain included which causes the brain fog I mentioned, the heart is affected causing cardiogenic symptoms, kidneys and even the adrenal glands are affected by COVID which can be part of the reason we see increased anxiety and some other mental health issues."

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Who is at Risk for Long COVID and Why?

older woman doing a puzzle

According to Dr. Harris, "Everyone is at risk for long COVID. If you look at the statistics, it is estimated that 1/3 of the population that experiences COVID can experience long COVID. That's 55 million Americans that could experience this. Just because you're asymptomatic does not decrease your risk. Of Children who have Multisystem inflammatory syndrome (MISC), two thirds experienced asymptomatic acute COVID infections but later developed long term effects from COVID."

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How Long COVID Can Affect Daily Life and Overall Well-Being

Woman Having Backache While Sitting On Sofa

Dr. Harris explains, "We've seen variation in what people experience with long COVID with clinical outcomes. The most prominent things that we see are fatigue, exertional fatigue, malaise, upper respiratory issues, brain fog. We know that certain individuals are at risk for disability and can not work. There has been a bump in short term disability from COVID. We've seen people exit the work force and be at the point where they can't work as long because of fatigue. We're also seeing that long COVID may be episodic with periods of normalcy and then periods of fatigue or other symptomatology from long COVID that spike after initial infection." Contact a medical professional if you have this issue, 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.

Heather Newgen
Heather Newgen has two decades of experience reporting and writing about health, fitness, entertainment and travel. Heather currently freelances for several publications. Read more about Heather