News Release | June 5, 2024, National Academies

WASHINGTON — A new report from the National Academies of Sciences, Engineering, and Medicine presents conclusions about Long COVID diagnosis, symptoms, and impact on daily function — including that Long COVID can cause more than 200 symptoms, and that a positive COVID-19 test is not necessary to make a Long COVID diagnosis. 

Since the onset of the COVID-19 pandemic in 2020, many individuals infected with the virus have continued to experience lingering symptoms for months or even years following acute infection. In a 2022 survey, 3.4 percent of U.S. adults and 1.3 percent children reported they were experiencing Long COVID symptoms at the time of the survey.

The new report says that some health effects of Long COVID, including chronic fatigue and post-exertional malaise, cognitive impairment (sometimes referred to as “brain fog”), and autonomic dysfunction, can impair an individual’s ability to work or attend school for six months to two years or more after COVID-19 infection. It can be difficult to clinically assess these health effects, or to determine their severity and effect on a person’s ability to function. They also may not be captured in the Social Security Administration’s Listing of Impairments, which is used as an initial screening step in determining disability.

Even patients with a mild case of COVID-19 can go on to develop Long COVID with severe health effects. Risk factors for poor functional outcomes from Long COVID include being female, lack of or inadequate vaccination against COVID-19, preexisting disability or comorbidities, and smoking. A greater number of or more severe Long COVID symptoms are correlated with decreased quality of life, physical functioning, and ability to work or perform in school.

“Diagnosing, measuring, and treating Long COVID is complicated. This disease, which has existed in humans for less than five years, can present differently from person to person and can either resolve within weeks or persist for months or years,” said Paul Volberding, professor emeritus in the department of medicine at the University of California, San Francisco, and chair of the committee that wrote the report. “Our report seeks to offer a clear summary of what research has found so far about diagnosing Long COVID, and what the disease can mean for an individual’s ability to function in their daily lives.”

“This report offers a comprehensive review of the evidence base for how Long COVID may impact a patient’s ability to engage in normal activities, such as going to work, attending school, or taking care of their families,” said Victor J. Dzau, president of the National Academy of Medicine. “Its findings will be useful to anyone attempting to understand how Long COVID may affect the millions of people in the U.S. who have reported symptoms.”

The report also concludes:

• A formal COVID-19 diagnosis or positive test is not necessary to consider Long COVID diagnosis.
  
• Long COVID can cause more than 200 symptoms and affects each person differently. Long COVID is associated with a wide range of new or worsening health conditions impacting multiple organ systems. These can include cardiovascular, respiratory, mental health, gastrointestinal, nervous system, and metabolic symptoms. The report includes a full listing of all symptoms and conditions that have been associated with Long COVID.
  
• The risk of Long COVID increases with the severity of COVID-19 illness. The report estimates that people whose infection was sufficiently severe to necessitate hospitalization are 2 to 3 times more likely to experience Long COVID than are those who were not hospitalized, and among individuals who were hospitalized, those requiring life support in an intensive care unit may be twice as likely to experience Long COVID. However, people with mild disease can also develop Long COVID, and given the much higher number of people with mild versus severe disease, they make up the majority of people with Long COVID.
  
• There is no curative treatment for Long COVID. Management of the condition is based on current knowledge about treating its symptoms and health effects. As with other complex chronic health conditions, medical treatment for Long COVID is focused on managing symptoms and optimizing quality of life and function.
  
• Recovery from Long COVID varies among individuals, and the data on recovery trajectories are rapidly evolving. While there is evidence that many people with Long COVID symptoms have improved by 12 months, data beyond that time frame is limited but suggestive that recovery might plateau or progress at a slower rate.
  
• Socioeconomic status, geographic location, health literacy, and race and ethnicity all affect access to health care — and have contributed to disparities in access to COVID-19 testing, vaccination, and therapeutics, including treatments for acute infection and specialized rehabilitation clinics for Long COVID.
   
• Complex, infection-associated chronic conditions are not new, and Long COVID shares many features with conditions like myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and fibromyalgia.
  
• Although the majority of children, including adolescents, recover fully from COVID-19, some develop Long COVID and experience persistent or intermittent symptoms that can reduce their quality of life. This can result in increased school absences and decreased participation and performance in school, sports, and other social activities. The trajectory for recovery in children and adolescents is better than in adults. More research is needed to understand Long COVID in children, as information from adult studies may not be directly applicable.

The report says that Long COVID is a relatively novel and rapidly evolving condition. Continued research on its effects, both on individual health outcomes and societal implications, will be necessary to effectively understand, treat, and manage it.