In the growing effort to unravel the mysteries of long COVID, a new study found that one out of 10 people appear to suffer symptoms from the disease six months after an infection.
The research, based on data collected from nearly 10,000 adults, took a major step toward defining key symptoms of the lingering ailment — such as fatigue, brain fog, loss of taste and smell — a crucial step in helping patients and their doctors better understand the long-term effects of COVID.
“Sometimes I hear people say, ’Oh, everybody’s a little tired,’” Dr. Leora Horwitz of NYU Langone Health, one of the study authors, told the Associated Press. “No, there’s something different about people who have long COVID and that’s important to know.”
The National Institutes of Health-funded study, published this week in JAMA, also found: Women are slightly more likely to develop long COVID, the chance increases with additional infections, and more acute cases are more likely to cause long COVID.
The condition known as long COVID is technically referred to by the researchers as “postacute sequelae of SARS-CoV-2 infection” or PASC. The self-reported symptoms are numerous, but post-exertional malaise, fatigue, and brain fog, along with gastrointestinal issues and changes to hearing and taste and smell were among the most common.
Millions worldwide have had long COVID, with dozens of widely varying symptoms. Scientists still don’t know what causes it, why it only strikes some people, how to treat it -– or even how to best diagnose it. Better defining the condition is key for research to get those answers.
The “important” paper “is probably the best descriptive study of long COVID that we have,” said Dr. John Swartzberg, clinical professor emeritus of infectious diseases and vaccinology at UC Berkeley’s School of Public Health. He said that though not earth-shattering, careful detailed descriptions of symptoms are the foundation of medical advancement.
“In the history of medicine, the way we learn things at first is all descriptive,” Swartzberg said, with a nod to Hippocrates.
The symptoms associated with long COVID range from debilitating to mild, and official definitions and diagnoses are still being developed, but other reports suggest millions of people in the country have experienced new or lingering symptoms more than 30 days, and for some years, after a COVID infection.
The Researching COVID to Enhance Recovery (RECOVER) Initiative recruited nearly 10,000 adults for the study, along with over 8,000 children in a separate cohort.
By some previous estimates, roughly 1 in 3 COVID-19 patients have experienced long COVID. That’s similar to NIH study participants who reported getting sick before the omicron variant began spreading in the U.S. in December 2021. That’s also when the study opened, and researchers noted that people who already had long COVID symptoms might have been more likely to enroll.
The new study zeroed in on a dozen symptoms that may help define long COVID: fatigue; brain fog; dizziness; gastrointestinal symptoms; heart palpitations; sexual problems; loss of smell or taste; thirst; chronic cough; chest pain; worsening symptoms after activity and abnormal movements.
The researchers assigned scores to the symptoms, seeking to establish a threshold that eventually could help ensure similar patients are enrolled in studies of possible long COVID treatments, as part of the NIH study or elsewhere, for apples-to-apples comparison.
Horwitz stressed that doctors shouldn’t use that list to diagnose someone with long COVID — it’s a potential research tool only. Patients may have one of those symptoms, or many -– or other symptoms not on the list — and still be suffering long-term consequences of the coronavirus.
Everyone’s doing studies of long COVID yet “we don’t even know what that means,” Horwitz said.