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

The initial infection may be just the beginning.
FACT CHECKED BY Emilia Paluszek

A new study just came out confirming what too many suffering Americans already knew: A COVID-19 infection, even a mild one, can at times result in debilitating symptoms that can last longer than a year—potentially a lifetime. It's called Long COVID, or Post-COVID Syndrom (PCS) or post-acute sequelae of SARS-CoV-2 (PASC). And it can happen to up to 30% of those who get COVID. "Quite honestly, anybody can develop it," says  Dr. Billie Schultz, a Mayo Clinic physical medicine and rehabilitation expert. "So they've looked at who is more likely to have these symptoms that linger, and…honestly, anybody can. It doesn't depend on the severity of the COVID infection. It doesn't necessarily depend on the patient's age. It doesn't necessarily depend on their educational level. It can really be anybody that we see. Common signs and symptoms that linger over time include" the following. Read on—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.


You May Have "Brain Fog"

Woman fainted

"Fatigue and what's being called 'brain fog' are turning out to be some of the most common issues for long-hauler patients recovering from COVID-19," says the Mayo Clinic. It results in a lack of concentration or memory problems. Long COVID "seems to be more of an inflammatory process," says Schultz. "There are instances where there is an infection causing this, but for the most part, it's an inflammatory process within the brain. So if I MRI somebody's brain, it's going to look the exact same because it's more at this microscopic level. And also we don't necessarily know how long the inflammation lasts, but it does change the chemistry and changes how the brain processes things."


You May Have Fatigue

woman laying on bed with a phone in her hand.

Dr. Anthony Fauci, the chief medical advisor to the President and the director of the National Institute of Allergy and Infectious Diseases, has said fatigue is a hallmark symptom of Long COVID, along with brain fog and myalgia. It affects the majory of patients, according to a Mayo Clinic study published in Mayo Clinic Proceedings—and many of them were hearty, active people before this. "Most patients in the study had no preexisting comorbidities prior to COVID-19 infection, and many did not experience symptoms related to COVID-19 that were severe enough to require hospitalization," says Greg Vanichkachorn, M.D., medical director of Mayo Clinic's COVID-19 Activity Rehabilitation program and first author of the study. "Most of the patients had normal or nondiagnostic lab and imaging results, despite having debilitating symptoms. That's among the challenges of diagnosing PCS in a timely way and then responding effectively."


You May Have Shortness of Breath or Difficulty Breathing

COVID is a respiratory disease, and while it can disrupt all your systems, your lungs are vulnerable, leading to shortness of breath or difficulty breathing. Additionally, COVID can cause heart trouble, which can also lead to a tightness in your chest or shortness of breath.


You May Have Joint or Muscle Pain

young man sitting on couch with kidney pain
Shutterstock / Syda Productions

Dr. Fauci calls the aches and pains associated with Long COVID as "myalgia." This kind of pain can develop "almost anywhere in your body, including your neck, back, legs and even your hands," says the Mayo Clinic. Sometimes it can even feel like other symptoms—one man's costochondritis, which was a pain in his ribs, resembled a heart attack. 

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You May Have Chest Pain

Man having chest pain - heart attack, outdoors

The toll COVID takes on the heart can cause lasting damage. It "can damage heart muscle and affect heart function," says cardiologist Wendy Post, M.D. "There are several reasons for this. The cells in the heart have angiotensin converting enzyme-2 (ACE-2) receptors where the coronavirus attaches before entering cells. Heart damage can also be due to high levels of inflammation circulating in the body. As the body's immune system fights off the virus, the inflammatory process can damage some healthy tissues, including the heart. Coronavirus infection also affects the inner surfaces of veins and arteries, which can cause blood vessel inflammation, damage to very small vessels and blood clots, all of which can compromise blood flow to the heart or other parts of the body."


You May Have Headaches

Young woman sitting on a couch, holding her head, having a strong headache. Close up Portrait of young woman with headache.

"The thing that happens when you get this blood vessel inflammation is there's vasodilatation. What does vasodilation cause? Headaches, migraines? Yeah," says Long COVID expert Dr. Bruce Patterson. "And the vascular information of course causes the brain fog and what we call tinnitus or ringing in the ears."

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You May Have Worsened Symptoms After Physical or Mental Activities

Tired woman holding her head with her hands.

Imagine being able to take a walk, do the dishes or power through a full day's work over Zoom—only to have a complete physical breakdown within two days. This "post-exertional malaise" is one of the most frustrating and hard to manage symptoms for long haulers. How do you pinpoint what X action led to what Y reaction? Apps like MyMee can help you track that with a specialist, but Long Haulers often find the only solution is to…not move much. It's bad. 


You May Have Sleep Problems

Worried young woman laying in bed sleepless at night

After reading all of the symptoms above, you can imagine why Long Haulers have trouble sleeping. Whether it's inflammation in the brain, pains waking you up, anxiety over the syndrome or a disruption of your former routine (no exercise???), there are a number of reasons why many Long Haulers are either insomniacs or have trouble falling asleep. It's a shame because rest is what they need. 

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You May Have Any Number of Other Symptoms

Sick woman trying to sense smell of half fresh orange, has symptoms of Covid-19, corona virus infection - loss of smell and taste

There are more than 200 Long COVID symptoms cataloged, including depression or anxiety, a sustained loss of smell or taste, a fast or pounding heartbeat, a cough, a continuing fever, fainting, heart trouble, dizziness when you stand and more. "As we've learned from a year of dealing with COVID-19, the signs and symptoms of viral and of the viral infection can vary widely from individual to individual," says the Mayo Clinic's Dr. Halena Gazelka. "And that's true of the long-term effects as well. Some people recover very quickly while others seem to suffer effects for quite a long period of time." 

How long? No answers yet. For those who have brain fog: "We don't know, but we are using information from other conditions that affect the brain and cause cognition or brain fog type symptoms as kind of our surrogate for how we manage and how we anticipate improvement," says Schultz. "And so, as an example, using a patient who had a concussion as an example, we do expect improvement in those patients. And so we're saying, and that's a change in brain chemistry with a concussion. And so we're hopeful that we'll continue to see improvement in these patients." 


What to Do If You Feel You May Have Long COVID

Healthcare worker at home visit

"Probably the first thing, and the most important thing, is to make sure you seek help with medical providers and given that COVID-19 and especially Long Hauler syndrome—they syndromes can affect multiple organ systems," says Schultz. "People can have fatigue. People can have breathing problems as well as brain problems. It's important to seek care at a multidisciplinary medical center where you can see specialties in all these areas." 

"As the pandemic continues, we expect to see more patients who experience symptoms long after infection, and health care providers need to prepare for this, know what to look for, and know how to best provide for their patients' needs," says Dr. Vanichkachorn.

So ask your doctor about multidisciplinary care, 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