They hadn’t been hospitalized. They were relatively young and otherwise in good health, without the underlying conditions like obesity and diabetes that are known to make Covid-19 worse. And yet, months after their bodies had seemingly fought off the coronavirus, they still felt quite ill.
These patients have labeled themselves “Covid long-haulers.” What they’re suffering from, they say, is “long Covid.” As a group, they report a strange hodgepodge of symptoms, including fatigue, pain, shortness of breath, light sensitivity, exercise intolerance, insomnia, hearts that race inexplicably, diarrhea and cramping, memory problems and a debilitating “brain fog” that can at times make it hard to put a cogent sentence together. In many cases, these symptoms continue unabated from the acute phase of the illness — as if, on some level, the infection never really went away.
Avindra Nath, clinical director of the National Institute of Neurological Disorders and Stroke, told me that when fighting a pathogen, the immune system sometimes conducts a very precise and surgical attack, working like a guided missile. But when that approach fails, it can begin “blanket bombing,” as he puts it. Once the infection is gone, tamping down the resulting firestorm can prove challenging. “You have persistent immune activation,” he says. And that lingering inflammation could drive many symptoms.