A recent study by researchers at King’s College London revealed that older people, women, and those with a myriad of symptoms in their first week of COVID-19 are more likely to develop “long COVID.”
The paper defines “long COVID” as having symptoms for more than four weeks. A shorter bout of COVID-19 typically causes symptoms for less than 10 days without relapse.
The findings add to a growing field of research suggesting the coronavirus may have debilitating long-term health consequences. An early October study published in the Journal of the American Medical Association found that 87% of 143 coronavirus patients at Rome’s biggest hospital had at least one symptom nearly two months later. More than half still experienced fatigue.
The King’s College study surveyed data from 4,182 cases collected through the COVID Symptom Study app. It found that one in seven people fall ill for at least four weeks, one in 20 people are ill for at least eight weeks, and one in 45 people are ill for at least 12 weeks.
The U.K. Department of Health and Social Care responded to the report by publishing a short video of people sharing stories about their experiences with long COVID. Many report feeling better after a few weeks before symptoms abruptly return worse than before. Loss of smell and appetite, aches, fatigue, and breathing issues make returning to life difficult and many fear debilitating long-term health impacts.
“It’s almost like there’s inflammation in my body that’s bouncing around and it can’t quite get rid of it, so it just pops up and then it goes away and pops up and goes away,” long COVID patient Vicky Bourne told the BBC.
The study results show anyone can develop long COVID, but there are some factors that enhance risk. Women under 60 are twice as likely as men to experience coronavirus symptoms for more than a month.
“This is a similar pattern to what you see in autoimmune diseases,” said Professor Tim Spector from King’s College London. “Things like rheumatoid arthritis, thyroid disease, and lupus are two to three times more common in women until just before menopause, and then it becomes more similar.”
Overall, those who experience five or more symptoms within their first week of COVID-19 are more likely to experience lingering symptoms, according to the King’s College study. Some postulate premature blood tissue aging and altered organ functions as a cause, but health experts remain unsure about what specific symptoms cause long COVID.
“The theory I’m working on is a premature aging of the small blood vessels that deliver oxygen and nutrients to the tissues,” Professor David Strain told BBC. Strain is seeing COVID-19 patients at his Chronic Fatigue Syndrome clinic. He warned that “it is difficult to figure out treatments” until we figure out what is causing long COVID.
“The findings of the COVID Symptom Study are stark and this should be a sharp reminder to the public, including to young people, that COVID-19 is indiscriminate and can have long-term and potentially devastating effects,” Health and Social Care Secretary Matt Hancock said.
The study’s goal is to develop early warning signals so patients at risk of long COVID can get the extra care—and early treatment—they need.
“It’s important we use the knowledge we have gained from the first wave in the pandemic to reduce the long-term impact of the second,” Dr. Claire Steves said in a news release. “This should pave the way for trials of early interventions to reduce the long term effects.”