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Expert committee proposes a new working definition of Long COVID

  • Update
  • July 3, 2024

The National Academies of Sciences, Engineering, and Medicine (NASEM) recommends that researchers, healthcare professionals, and government agencies adopt its new working definition of Long COVID to help ease the suffering of millions of people.

On June 11, 2024, The National Academies of Sciences, Engineering, and Medicine (NASEM) released a report proposing a consensus definition of Long COVID. The purpose of this definition is to help ensure everyone experiencing symptoms of Long COVID can receive a consistent diagnosis and get appropriate care, aid awareness efforts, and help align research efforts.

Older woman with hand on forehead looking stressed.

NASEM created this definition at the request of the Office of the Assistant Secretary for Health (OASH) and the Administration for Strategic Preparedness and Response (ASPR) within the U.S. Department of Health and Human Services (HHS). HHS is currently reviewing NASEM’s definition and recommendations for its use. HHS is also working with other government agencies addressing the long-term impacts of COVID, including the National Institutes of Health (NIH), to raise awareness about NASEM’s definition and recommendations.

NASEM’s definition states:
Long COVID is an infection-associated chronic condition (IACC) that occurs after SARS-CoV-2 infection and is present for at least 3 months as a continuous, relapsing and remitting, or progressive disease state that affects one or more organ systems.


Infection-Associated Chronic Conditions (IACC):
Some infections, or diseases caused by microorganisms (bacteria, fungi, parasites, and viruses), can cause long-lasting symptoms even after the original infection has been treated. IACCs are a broad category of conditions that include Long COVID, postural orthostatic tachycardia syndrome (POTS) and forms of dysautonomia, myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), Lyme-associated chronic illnesses, and Epstein-Barr virus.

Long COVID can show up in multiple ways:

  • Long COVID symptoms can affect any part of the body and different parts of the body at the same time.
  • Long COVID can include one or more of hundreds of signs, symptoms, or diagnosable conditions.
  • Symptoms may include shortness of breath, fatigue, difficulty concentrating, post-exertional malaise, and many others.
  • Long COVID may also lead to or worsen conditions such as cardiovascular disease, anxiety, mood disorders, POTS and forms of dysautonomia, ME/CFS, fibromyalgia, diabetes, and others.

Important aspects of Long COVID:

  • People can develop Long COVID after getting COVID, whether it is asymptomatic, mild, or severe. People can receive a Long COVID diagnosis even if they never tested positive for COVID.
  • Long COVID can develop immediately or any time after a COVID infection, including months later, even for people who appear to have recovered.
  • Long COVID can affect people of all ages, sexes, races, ethnicities, and backgrounds.
  • Long COVID can worsen pre-existing health conditions or show up as new conditions.
  • People suffering from Long COVID have symptoms for at least 3 months, but those symptoms can get better or worse—or even come and go—during that time.
  • Long COVID symptoms can range from mild to severe. Symptoms can get better over a period of months or last for months to years.
  • Diagnosing Long COVID can be done through observation and treatment by a healthcare provider, but there is no specific test or measurement that can conclusively diagnose Long COVID.
  • Long COVID symptoms can affect everyone differently. Some people with Long COVID may feel so sick that they find it difficult to work, go to school, take care of their families, or take care of themselves without assistance. Long COVID can have a profound physical and emotional impact on patients as well as their families and caregivers.

NASEM’s definition is not a diagnosis. It only provides guidance that can help healthcare providers recognize Long COVID and its impact on their patients. NASEM’s definition also does not include any recommendations for treating Long COVID or its symptoms.

Read NASEM’s working definition of Long COVID (PDF, 237 KB)

A group of diverse health experts and Long COVID patients worked together to create this definition. Several members of this group—the Committee on Examining the Working Definition for Long COVID—are people involved with RECOVER.

  • Karyn Bishof (RECOVER Ancillary Studies Oversight Committee)
  • Betty Diamond, MD (RECOVER Executive Committee)
  • Liza Fisher (RECOVER Representative)
  • Jerry Krishnan, MD, PhD (RECOVER Adult Cohort Coordinating Committee)
  • Andrea B. Troxel, ScD (Co-principal investigator, RECOVER Clinical Science Core; RECOVER Autopsy Cohort Coordinating Committee)
  • Monica Verduzco-Gutierrez, MD (Co-principal investigator of RECOVER studies taking place at the University of Texas at San Antonio)

The committee reviewed existing working definitions of Long COVID as well as Long COVID research, including RECOVER study findings. The committee also reviewed feedback provided by more than 1,300 people impacted by and interested in Long COVID, including caregivers, patients, patient advocates, and community members.

The committee recommends that OASH’s Office of Long COVID Research and Practice (OLC) lead efforts to update this working definition regularly as the scientific community learns more about Long COVID.

Read the NASEM Committee’s final report, A Long COVID Definition: A Chronic, Systemic Disease State with Profound Consequences

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