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Sure Signs You've Already Had COVID, Says Virus Expert


"Unfortunately, there are many, many questions that we do not have answers for about what is referred to as long COVID," said virus expert Dr. Michael Osterholm on the latest episode of his podcast. The condition involves "a wide range of new, returning and ongoing health problems that people experience for four more weeks after being infected with SARS-CoV-2." Noting that long COVID now qualifies as a disability under the Americans With Disabilities Act, Osterholm unpacked some of the most common symptoms, along with what science knows about the mysterious syndrome now. Read on to find out more—and to ensure your health and the health of others, don't miss these Sure Signs You've Already Had COVID.


Shortness Of Breath Or Difficulty Breathing 

Woman suffering an anxiety attack alone in the night

Breathing trouble was a hallmark symptom of the first waves of COVID, and with long COVID, that can persist long after the virus has cleared the body. 

Osterholm noted that a study published in November 2021 found that being female, having respiratory symptoms in the acute phase of COVID infection, and having severe symptoms were all associated with the greater risk of developing long COVID. "UK data published in September showed that symptomatic individuals were over two-and-a-half times more likely to develop long COVID of any severity than asymptomatic individuals," he said.



Woman recovering from an illness in bed at home.

One of the most common symptoms of COVID-19—or any viral infection—fatigue is a sign the body is fighting off a virus. But in some people with COVID, the fatigue doesn't go away and can be debilitating. They may even not be able to return to work or regular activities. "We may not know the exact prevalence, but we know that long COVID is impacting a significant proportion of those previously infected with SARS-CoV-2, often to the extent that it interferes with their everyday life," said Osterholm.


Dizziness or Brain Fog

Vertigo illness concept. Man hands on his head felling headache dizzy sense of spinning dizziness,a problem with the inner ear, brain, or sensory nerve pathway.

"A Johns Hopkins group has placed an emphasis on post COVID-19 POTS [postural orthostatic tachycardia syndrome], which affects heart rate and blood pressure," says Osterholm. If you experience dizziness on standing, a racing heartbeat, fatigue or brain fog, you should be assessed for POTS, so it can be treated. You may have had the condition before COVID, in which case the virus may have worsened it. 


Depression Or Anxiety

Woman lying at bed.

COVID can cause neurological effects, such as depression and anxiety. Those symptoms can persist, possibly exacerbated by the challenges of long COVID. 


Loss Of Taste Or Smell

woman trying to sense smell of half fresh orange, has symptoms of Covid-19

Some people find that they lose smell or taste during a COVID bout and that it just doesn't come back, at least to previous levels, after they've technically recovered.

What causes long COVID? Osterholm said scientists aren't yet sure but have theories. "It's likely that there is a wide array of biologic processes that lead to long COVID," he said, including:

  • Autoimmune issues. The body may produce auto-antibodies or antibodies that attack your own tissue. "That cause complications after the virus has been cleared by the body," similar to other autoimmune conditions like Epstein-Barr.
  • Chronic inflammation. "Elevated levels of interleukin-6, a cytokine that indicates an inflammatory process, has been seen in long COVID patients," said Osterholm.
  • Persistent, low-level infection in tissues like the intestine, liver, or brain, which can continue to cause damage. "A recent article that is still in pre-print found T-cell dysregulation" in long COVID patients, noted Osterholm, "which is consistent with low-level ongoing infection."


Other Multi-Organ Effects

man having heart attack

These effects can include problems with the heart, lungs, kidneys, skin, and brain, and particularly the multi-system inflammatory syndrome in children, said Osterholm. 

"Among children and adolescents, studies have reported between less than 1% to as high as 66% of the pediatric COVID-19 cases could result in long COVID symptoms," he added. "But a growing consensus is that about 10% of pre-Omicron cases result in long COVID."

Although the numbers may be relatively low, long COVID is having measurable effects on society. A recent study in the UK found that from March 2020 to September 2021, healthcare workers lost 1.82 million work days because of long COVID. It's also estimated that 2% of the population of England—about 1.3 million people—are experiencing long COVID and about 500,000 have had symptoms for more than a year, said Osterholm.


How to Stay Safe Out There

Doctor Giving Older Woman Corona Virus Vaccine Injection In Hospital

Follow the fundamentals and help end this pandemic, no matter where you live—get vaccinated ASAP; if you live in an area with low vaccination rates, wear an N95 face mask, don't travel, social distance, avoid large crowds, don't go indoors with people you're not sheltering with (especially in bars), 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. Read more about Michael