Rachel Robles contracted COVID in March 2020. The 27-year-old data analyst hasn’t gone a day without symptoms since then. Most doctors didn’t believe her when she described how she had endured such crippling fatigue from running the Brooklyn Half Marathon last year that her couch felt like quicksand. How, despite her technical education, she suddenly had trouble getting numbers together. No matter how many times she breathed, she always felt hungry for air.
Three months later, a doctor told her: “COVID does not last 90 days. Either you get over it or you die.”
That dichotomy — in which the only possible outcomes of COVID are either full recovery or death — has turned out to be anything but true. Between 8 million and 23 million Americans are still sick months or years after being infected. Due to the bewildering array of symptoms known as long-term COVID, an estimated 1 million of those people are so disabled that they are unable to work, and that number is likely to increase as the virus continues to develop and spread. Some who have escaped COVID for a long time the first time get it after their second or third infection. “It’s a massive public health crisis in the wake of acute COVID infection,” said Linda Geng, a physician and co-director of Stanford Health Care’s long-term COVID clinic.
While it’s no longer debated that COVID is a real phenomenon — both the Centers for Disease Control and Prevention and the World Health Organization have acknowledged its existence — the science is so new that many questions remain about how to treat the condition. define, what causes it and how to treat it effectively. It has become clear that long-term COVID can take various forms. “Not everyone has the same disease,” meaning there are different causes, says Akiko Iwasaki, an immunologist at the Yale School of Medicine.
Scientists have proposed different but interconnected origin stories to explain these disparate symptoms: The coronavirus can damage organs, produce small blood clots, trigger autoimmunity, hide in tissues, or cause new and persistent symptoms in other more subtle ways. To complicate matters, these stories are not mutually exclusive: several can occur simultaneously in a given patient, or one can cause another in an unfortunate sequence of events that keeps the patient in perpetual ill health. By taking the theories apart one by one, researchers are gaining a better understanding of this puzzling disease and moving closer to therapies that not only mask symptoms, but eliminate the cause.
Produced by Hunni Media for Knowable Magazine
Listening to patients
Many of the earliest insights into long-term COVID are drawn from the experiences shared by patients. A study by the Patient-Led Research Collaborative, a team of long-term COVID patients researching their condition, compiled a list of more than 200 different symptoms in 10 organ systems. These range from the most common complaints such as fatigue, cognitive impairment, shortness of breath, irregular periods, headaches, palpitations, difficulty sleeping and anxiety and depression, to other conditions such as double vision, peeling skin, hair loss, ringing in the ears, tremors, food allergies and sexual dysfunction. The constellation of reported symptoms can vary from person to person and even change over the course of the condition.
Because there is no agreed-upon definition of long-term COVID, no simple diagnostic test, and no way to clearly distinguish one subtype from another, the various manifestations of this mysterious condition are often lumped under one big umbrella, confusing researchers. But emerging research provides the first evidence for several promising hypotheses.
One theory attributes the disease to persistent organ or tissue damage caused by the initial infection with SARS-CoV-2, the virus behind COVID-19. Although the coronavirus enters the body through the respiratory tract, it can travel through the bloodstream to infect the kidneys, heart, nervous system and gut. In the process, it can create waves of inflammation that reverberate throughout the body, causing collateral damage to multiple organs.
In one study, researchers at the University of Oxford compared brain scans of people before and after they got COVID and found that even mild cases can cause the brain to shrink by 0.2 to 2 percent more than in people who were not infected. Because adults typically lose about 0.2 percent of their brain volume each year in areas related to memory, that translates into a mental decline equivalent to aging 1 to 10 years. It’s too early to know if this effect is temporary or if people develop age-related conditions later in life.
