COVID-19 'long-haulers' feel virus's effects long after recovery

Q: My uncle tested positive for the coronavirus last winter and wound up in the hospital. He was lucky, and he recovered, but it is six months later and he still is not completely better. He says he's what's known as a "long-hauler." Can you please explain what that is, and why it happens?

A: From its earliest days, the coronavirus pandemic put science and medicine on the steepest of learning curves. The virus had never been seen before, and the disease that it causes, now known as COVID-19, was a complete unknown. As months passed and the data accrued, we continued to learn about the many ways the novel coronavirus affects the human body.

We've also become aware of the different trajectories the illness it causes can take. Some people, as we now know, develop only mild symptoms. Others have no symptoms at all. Some struggle with serious or fatal cases of COVID-19, while others experience moderate disease with complete recoveries. But as the number of cases continues to grow, and doctors share and pool their data, a troubling trend has emerged.

Unlike the flu, the disease that in many respects it resembles, COVID-19 is not always a short-term illness. For many people, as with your uncle, recovery becomes a long and uncertain process. A survey conducted by the Centers for Disease Control and Prevention last spring found that up to 35% of COVID-19 patients continue to feel the effects of the disease long after tests show they were virus-free.

This appears to be similar to what was seen with SARS (severe acute respiratory syndrome), the coronavirus-caused illness that first emerged in 2002. Some patients who had been hospitalized with SARS continued to experience impaired lung function two years after first becoming ill.

Patients who continue to experience lingering symptoms, now referred to as "post-COVID syndrome," have come to be known as long-haulers. Unlike the steady recoveries we make from a cold or the flu, long-haulers experience repeated setbacks. A day or two of good health will be followed by a sudden recurrence of fever or lung inflammation. Fatigue, exhaustion, chills and headache come and go and then come again. Some patients find themselves back in the hospital for treatment of acute symptoms. For many long-haulers, the cognitive difficulties that can accompany a severe bout of COVID-19 never completely vanish.

And, as the disease drags on with no end in sight, a growing number of people with post-COVID syndrome report dealing with feelings of anxiety and depression that interfere with daily life.

As with so many questions related to the novel coronavirus and COVID-19, the causes of post-COVID syndrome are not yet known. One promising line of inquiry is looking at whether viral particles that remain within the body may be setting off powerful immune reactions. Meanwhile, many COVID-19 long-haulers say they are finding emotional safe harbor in online support groups made up of fellow survivors. They exchange information, share strategies and find comfort in knowing that, in this particular long journey, they are not alone.

• Dr. Eve Glazier is an internist and associate professor of medicine at UCLA Health. Dr. Elizabeth Ko is an internist and assistant professor of medicine at UCLA Health. Send your questions to askthedoctors@mednet.ucla.edu.