It was just a couple of months into the pandemic when patients in online support groups began describing the phenomenon. In some emergency departments, they said, their complaints were largely being dismissed—or at the very least diminished—by health care professionals. The patients felt they were not being heard, or perhaps even were outright disbelieved.


The common thread through these comments was a basic one. Each of the patients had already been infected with COVID-19 and presumably had recovered, yet each was still dealing with symptoms of the disease—sometimes vague, sometimes nonspecific—that simply would not go away. Physicians and nurses, already overloaded with emergent cases of the virus, were baffled, often searching for other, more benign explanations for what they were being told.

We now have a term for those patients—and the truth is, “long hauler” only begins to describe the COVID-related ordeals they are enduring. Of all the facets of the virus we have dealt with in 2020, this one may ultimately prove the most difficult to recognize, much less combat.

Long-haul COVID patients carry their symptoms well beyond what we’ve come to understand as a “normal” course of recovery. It can last for weeks. For some long haulers, it has been months—and counting. And to the consternation of physicians and nurses on the front lines, the symptoms of these patients often present as so varied and relatively common that they defy a solid COVID-related diagnosis.

If a patient comes to the emergency department (E.D.) complaining of dizziness, forgetfulness and headache, for example, is that long-haul COVID or something else entirely? How about fatigue? A persistent cough? Muscle aches and insomnia? Relapsing fevers?

With little to go on, and lacking clinical guidance, some of us in the E.D. have instructed our patients to go home, get more rest, “try to relax.” We’ve offered reassurances that everything would be okay with more time, checked off the final diagnosis box for something like anxiety or chronic fatigue on our computers, and moved on to see our next patients.


But there’s a growing body of evidence to suggest that a surprising number of people are, in fact, COVID long haulers, and that hospital emergency departments and clinics may be dealing with them for months and months to come.

“Over the past few months evidence has mounted about the serious long-term effects of COVID-19,” said the World Health Organization Director-General, Tedros Adhanom, at an international long-COVID forum on December 9. At the same event, Danny Altmann, an immunologist at London’s Imperial College, said that his “guesstimate is that we probably have way more than five million people on the planet with long COVID.” The worldwide percentages of infection suggest that many of those people are living and suffering in the U.S.

Long COVID is neither well-defined nor well understood, in part because the research base is still in its infancy. The term “long hauler” is broadly used to characterize individuals whose symptoms persist or develop outside the initial viral infection, but the duration and pathogenesis are unknown. Late sequelae have been described even in young, healthy people who had mild initial infection. And symptoms are often described by long haulers as being relapsing and remitting in nature—they improve, only to be struck back down again.

This reporting of this entire phenomenon has been inside out. In fact, this may be one of the first syndromes which evolved from patients’ accounts on social media. As the early weeks and months passed, patients joined Facebook groups, Twitter feeds, and other online support groups—the Body Politic COVID-19 Support Group is one—to share stories of the myriad long-hauler symptoms that they were experiencing post-COVID, bringing visibility to the issue.

The persistent effects were wide-ranging and included cognitive issues like “brain fog” and memory or attention problems, shortness of breath, a racing heart, nausea, diarrhea, intermittent spiking fevers—on and on. “A lot of us have the experience of really actually not knowing whether we would wake up in the morning,” said event participant Margaret O’Hara, co-founder of Long Covid Support Group, which has 31,000 members. Members even began collecting data about themselves, organizing their own Patient-Led Research for Covid-19 group.

What has emerged from this self-reporting is the clear realization that long COVID is very real, that the chronic health manifestations can be quite debilitating, that the syndrome may affect a significant number of individuals, and that much more research and care provision are urgently needed.

“From my perspective, it appears that post-COVID symptoms tend to be more common, severe, and longer-lasting than other viral illnesses, such as influenza,” says Timothy Hendrich, a viral immunologist and infectious disease expert at University of California, San Francisco.

The cause? It’s not clear. A post–intensive care syndrome is well recognized whereby patients, following discharge after a critical illness, can suffer from impairments of thinking, mental health and physical function that can last up to a year. The catch here is that long-haul COVID patients experiencing similar impairments have not all been hospitalized or critically ill.

This may be due to an immune-inflammatory response gone amok, or perhaps to ongoing viral activity. Says Hendrich, “The etiologies are almost certainly multifactorial, but may involve overzealous immune responses, cardiopulmonary or systemic inflammation, vascular inflammation or clotting disorders, and direct damage from viral replication during acute illness.” We currently have no proven treatments for these type of long-term post-COVID symptoms, he added.

One challenge is getting a real picture of how many people are affected. In a recent study in the journal Clinical Microbiology and Infection, a two-month follow-up of 150 adults with only mild to moderate COVID cases found that two thirds of them were still experiencing symptoms, most commonly shortness of breath, loss of smell and taste, and/or fatigue. Another study by Italian researchers, covering 143 COVID patients who had been discharged from the hospital, found that only about one in eight was completely free of symptoms 60 days from the beginnings of the illness.

One of the largest surveys so far, the King’s College London study, had four million users in the U.K. enter their ongoing symptoms on a smartphone app. The researchers reported that around 10 percent of patients had persistent symptoms for one month, with 1.5 to 2 percent having sustained symptoms at three months. As Hendrich suggests, this idea of “how many” is a moving target that will require more study and analysis.

King’s College researchers, reviewing their data from the COVID Symptom Study, identified patterns that suggested long COVID was twice as common in women as men, and the median age was 45. A non–peer reviewed study of approximately 4,100 people from the same data set found that older people, women, and those with more than five symptoms during their first week of illness were more likely to develop long COVID.

Early clinical studies have shown that COVID patients may experience complications like myocarditis (inflammation of the heart), abnormal heart rhythms and other cardiac sequelae weeks after contracting the virus. These conditions may help explain why some long haulers experience shortness of breath, chest pain or their heart racing. One non–peer reviewed study, involving 139 health care workers who developed coronavirus infection and recovered, found that about 10 weeks after their initial symptoms, 37 percent of them were diagnosed with myocarditis or myopericarditis—and fewer than half of those had showed symptoms at the time of their scans.

Persistent shortness of breath—not being able to climb up a few flights of stairs, for example, or being unable to complete usual exertional activities without getting winded—are complaints repeatedly seen on long-COVID forum sites. Small studies have found persistent lung findings like fibrosis (a form of lung scarring), perhaps explaining these symptoms. A retrospective multicenter study published in the Lancet of 55 recovered noncritical patients found that over 60 percent of patients had persistent symptoms three months after discharge, while just over 70 percent had abnormal findings on their lung CT scans. A quarter had demonstrable reductions in lung function.

Long haulers also have commonly described neurologic symptoms that include dizziness, headache, loss of smell or taste, etc. Carlos del Rio, at Emory University School of Medicine, wrote in a review that while stroke is not commonly reported acutely with COVID, encephalitis (inflammation of the brain), seizures and “brain fog” have been described several months post initial infection.

While there is much to learn, one study found that the most serious neurologic manifestations occurred in patients who experienced severe COVID infections, were older and had comorbidities. Anthony Fauci has expressed concern that some long haulers may develop myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) which has been linked to another coronavirus, severe acute respiratory syndrome (SARS). Several viruses including SARS-CoV-1, HIV, Middle East respiratory syndrome (MERS), polio, the chicken pox virus, etc. have been known to trigger delayed neurological sequelae.

Researchers are carefully monitoring mental health outcomes, too. Unquestionably, the longer-term psychosocial effects this virus is exacting on COVID survivors have yet to be fully elucidated. Anxiety, hopelessness, depression, even postraumatic stress disorder —especially in health care workers or patients following ICU experiences—have all been reported and need further study.

Amid all this there lies some good news. First, physicians and our medical communities now are much more aware of long-hauler syndrome. Post-COVID clinics now exist, offering a much-needed multidisciplinary and integrated approach. The Neuro COVID-19 Clinic at Northwestern Memorial Hospital, for example, has been very busy, according to its director, Igor Koralnik.

Research studies may well shine a brighter light on the symptoms of long-COVID patients, affording us a better understanding of who gets this condition and why, and suggesting possible interventions. Yet we’re still in early stages: The National Institutes of Health ClinicalTrials.gov Web site shows fewer than a dozen post-COVID trials currently planned in the U.S., while scientists reported from the Long COVID forum there are only 45 long-COVID projects underway worldwide, out of some 5,000-plus total COVID research projects.

It’s a situation we should be prepared to face. In Del Rio’s words, “hundreds of thousands, if not millions” of individuals in the U.S. may wind up dealing with a multitude of adverse physical and mental health effects over a long term—and some anecdotal accounts of children experiencing long-haul symptoms are especially worrisome.

This may not be the aspect of COVID we thought we’d be seeing, but it’s the aspect we are going to be dealing with—and for some time. As Tim Spector of King’s College wrote in the foreword of a report for the Tony Blair Institute for Global Change, “This is the other side of Covid.” Long after we’ve implemented strategies for dealing with the first wave of infection, our physicians are going to be seeing the many waves that follow.