23% of Patients With COVID Report Long-Haul Symptoms

Ralph Ellis

June 25, 2021

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A study of almost 2 million COVID-19 patients found that 23.2% of them sought treatment for COVID-related symptoms a month or more after being diagnosed.

"Many patients recover from COVID-19 within a few weeks, but some exhibit persistent or new symptoms more than four weeks after first being diagnosed," with some displaying symptoms up to nine months later, a study by the nonprofit FAIR Health said

FAIR Health studied the insurance records of 1.9 million COVID patients between February 2020 and February 2021. The major findings of the study were:

  • A month after diagnosis, about 50% of hospitalized patients reported symptoms, compared to 27.5% of patients who had symptoms and weren't hospitalized and 19% who were asymptomatic.

  • The top post-COVID symptoms were pain, breathing difficulties, hyperlipidemia (high cholesterol), fatigue, malaise, and hypertension.

  • The most common mental health conditions reported were anxiety, depression, adjustment disorders, and tic disorders.

  • The risk of death 30 days after COVID diagnosis was 46 times higher for patients who were hospitalized and discharged than for patients who weren't hospitalized.

"One thing that was surprising to us was the large percentage of asymptomatic patients that are in that category of long Covid," Robin Gelburd, president of FAIR Health, told The New York Times.

"There are some people who may not have even known they had Covid," she said, "but if they continue to present with some of these conditions that are unusual for their health history, it may be worth some further investigation by the medical professional that they're working with."

The study notes that COVID-19 and long-haul COVID are new and relatively unstudied. The condition goes by different names, including long COVID, post-COVID syndrome, or post-acute sequelae of COVID-19 or of SARS-CoV-2 (PASC). FAIR Health said its study appears to be the largest conducted so far.

Theories about the cause of long-haul COVID include "persistent immune activation after the acute phase; initial damage from the virus, such as damage to nerve pathways, that is slow to heal; and persistent presence of low-level virus."

University of Washington researchers reported in February that about 33% of COVID-19 patients who were never sick enough to require hospitalization continue to complain months later of symptoms like fatigue, loss of smell or taste and "brain fog." 


FAIR Health: "A Detailed Study of Patients with Long-Haul COVID."

The New York Times: "Many Post-Covid Patients Are Experiencing New Medical Problems, Study Finds."

JAMA: "Sequelae in Adults at 6 Months After COVID-19 Infection."


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