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Kelly LaDue thought she was done with COVID-19 in the fall of 2020 after being tormented by the virus for a miserable couple of weeks.
“And then I started with really bad heart-racing with any exertion. It was weird,” says LaDue, 54, of Ontario, N.Y. “Walking up the stairs, I’d have to sit down and rest. And I was short of breath. I had to rest after everything I did.”
A year later, LaDue still feels like a wreck. She gets bad headaches and wakes up with pain all over her body on more days than not. She also experiences a sudden high-pitched whistling in her ears, bizarre phantom smells and vibrations in her legs. Her brain is so foggy most of the time that she had to quit her job as a nurse and is afraid to drive.
“These symptoms, they come and go,” she says. “You think: ‘It’s gone.’ You think: ‘This is it. I’m getting better.’ And then it’ll just rear back up again.”
Patients like LaDue have researchers scrambling to figure out why some people experience persistent, often debilitating symptoms after catching SARS-CoV-2. It remains unclear how often it occurs. But if only a small fraction of the hundreds of millions of people who’ve had COVID-19 are left struggling with long-term health problems, it’s a major public health problem.
“I think it’s the post-pandemic pandemic,” says Dr. Angela Cheung, who’s studying long COVID-19 at the University of Toronto. “If we are conservative and think that only 10% of patients who develop COVID-19 would get long COVID, that’s a huge number.”
“Not caused by one thing”
So far there are more theories than clear answers for what’s going on, and there is good reason to think the varied constellation of symptoms could have different causes in different people. Maybe, in some, the virus is still hiding in the body somewhere, directly damaging nerves or other parts of the body. Maybe the chronic presence of the virus, or remnants of the virus, keeps the immune system kind of simmering at a low boil, causing the symptoms. Maybe the virus is gone but left the immune system out of whack, so it’s now attacking the body. Or maybe there’s another cause.
“It’s still early days. But we believe that long COVID is not caused by one thing. That there are multiple diseases that are happening,” says Akiko Iwasaki, a professor of immunobiology at Yale University who is also studying long COVID-19.
But Iwasaki and others have started finding some tantalizing clues in the