What is long COVID? And what is my risk of getting it?

Over the past year, there's been a flurry of research published about long COVID. Dozens of these studies try to estimate the risk of having lingering symptoms months after a COVID infection.

But when you look closely at the data, a huge inconsistency emerges: The estimates of the prevalence of long COVID range wildly, from less than 5% to nearly 60% of total COVID cases. So what's going on?

"It can be really confusing, even to scientists," says Christina Pagel, who directs the Clinical Operational Research Unit at University College of London.