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Sure Signs You've Already Had COVID, Says Mayo Clinic

Long COVID, or PASC, may never go away.
FACT CHECKED BY Emilia Paluszek

More and more people are discovering a brutal truth: Once you get coronavirus, it can cause long-lasting damage, turning you into a "Long Hauler" with Long COVID, or PASC. A study in Mayo Clinic Proceedings found thousands of people have suffered myriad symptoms—and it could happen to you or anyone, young or old. "I think it's an argument for why we take this disease so seriously," says Dr. Gregory Poland of the Mayo Clinic, who studies the immunogenetics of vaccine response in adults and children. "People thinking, oh, especially young people, 'Mild disease, I might not even have any symptoms and I'm over it.' Whoa. The data is suggesting otherwise….We're gonna see more and more of the longer term consequences come out and we're going to need to study those as big as closely as we did the acute symptoms." Do you have Long COVID? Read on to the very end to see the symptoms the Mayo Clinic mentioned—and to ensure your health and the health of others, don't miss these Sure Signs You've Already Had COVID.


You May Feel Fatigue

tired man
nimis69/ Getty Images

80% of the Long Haulers studied by the Mayo Clinic had fatigue, and Dr. Anthony Fauci, the chief medical advisor to the President and the director of the National Institute of Allergy and Infectious Diseases, has also mentioned fatigue as a very common symptom among Long COVID patients. This fatigue isn't your usual sleepiness after a long day's work. It can crush you and make ordinary chores unimaginable and exercise or simple exertion impossible. That's one reason Dr. Fauci is so strenuously in favor of vaccines—including vaccines for children; imagine a bright-eyed kid too fatigued to function, in the prime of their life. "It may be that much to our dismay that children who get infected have long-term consequences that we don't fully appreciate right now," Fauci said this week. "For those reasons, one of transmissibility, one of the seriousness of disease and one of uncertainty about long-range consequences, I come down strongly on ultimately vaccinating our children."

RELATED: Signs You May Have Delta, According to Patients


You May Have "Neurological Complaints"

Woman fainted

Before COVID, not too many people worried about, or had even heard of, "brain fog"—what Fauci calls an "inability to concentrate." Unfortunately, Long Haulers are now all too aware of the affliction, which has plagued sufferers of Chronic Fatigue Syndrome for decades. The long term effects of the virus can lead to memory loss, difficulty understanding simple concepts—or even more debilitating effects like delirium and hallucinations. Long COVID "seems to be more of an inflammatory process," says Dr. Billie Schultz, a Mayo Clinic physical medicine and rehabilitation expert. "There are instances where there is an infection causing this, but for the most part, it's an inflammatory process within the brain." Said the study: "Symptoms including mood disorders, fatigue, and perceived cognitive impairment resulted in severe negative impacts on resumption of functional and occupational activities in patients experiencing prolonged effects."

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You May Have Cellular Damage


"We're really seeing a number of reports of people who report long-term fatigue, headaches, vertigo. Interestingly enough difficulties with cognition with cardio, respiratory fitness. And I think what we're going to find out is that a large portion, not all, but a large portion of that is likely to relate to the significant cellular level damage that this virus can cause," says Dr. Poland of the Mayo Clinic, who studies the immunogenetics of vaccine response in adults and children. "Evidences of myocardial damage, cardiomyopathy, arrhythmias, pulmonary scarring and fibrosis, and then, in the more acute phase extending out for a month or two has been this really interesting issue of coagulation abnormalities, which have been responsible for both small vessel and large vessel arterial and venous occlusion. So this, this can be a really wicked virus in some people."

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You May Have "Respiratory Complaints"

Woman having breath difficulties.

Shortness of breath or trouble breathing are hallmark symptoms of COVID-19; this you know. You may not know that what the Mayo Clinic, in its study, called "respiratory complaints" can last for months, potentially years. 

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You May Have These Other Issues Also

Man sitting on bed holding his head.

One study in the Lancet said there were more than 200 Long COVID symptoms. The Mayo Clinic paper mentioned "subjective cognitive impairment, sleep disturbance, and mental health symptoms. More than one-third of patients (34%) reported difficulties in performing basic activities of daily living. Only 1 in 3 patients had returned to unrestricted work duty at the time of the analysis. For most patients, laboratory and imaging tests showed no abnormalities or were nondiagnostic despite debilitating symptoms. Most patients required physical therapy, occupational therapy, or brain rehabilitation." 

RELATED: 5 Things to Never Do During The Delta Pandemic


What to Do if You Fear You Have Long COVID

Healthcare worker at home visit

Don't think Long COVID can't happen to you. "Most of the patients did not have COVID-19–related symptoms that were severe enough to require hospitalization, were younger than 65 years, and were more likely to be female, and most had no preexisting comorbidities before severe acute respiratory syndrome coronavirus 2 infection," wrote the authors.  If you fear this has happened to you, contact your medical professional. There is no cure for Long COVID but a doctor can try to treat your symptoms with existing techniques. 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.

Alek Korab
Alek Korab is a Co-Founder and Managing Editor of the ETNT Health channel on Eat This, Not That! Read more about Alek