Long COVID

​Long COVID is a heterogeneous condition that encompasses a wide spectrum of individuals with new or persistent symptoms following acute coronavirus disease 2019 (COVID-19).

A positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral test is not necessary to establish a diagnosis of long COVID. A long COVID diagnosis can be made on the basis of a previous patient-reported or clinical diagnosis of COVID-19.

Treatments are targeted at symptom palliation and improvement in quality of life.

Many patients can be managed effectively in primary care. Referral to a specialist may be required for ongoing management. Referral to a specialized or multidisciplinary long COVID clinic is recommended for those with severe or treatment refractory long COVID, where such services are available.

Long COVID is a general term for persistent and typically multisystem symptoms following acute COVID-19 infection. It usually presents with clusters of symptoms, often overlapping, which can fluctuate and change over time and can affect any system in the body.[1]National Institute for Health and Care Excellence. COVID-19 rapid guideline: managing the long-term effects of COVID-19. January 2024 [internet publication]. https://www.nice.org.uk/guidance/ng188

The World Health Organization defines post-COVID-19 condition (long COVID) as a condition that occurs in adults with a history of probable or confirmed SARS-CoV-2 infection, usually occurring 3 months from the onset of COVID-19 symptoms and lasting for at least 2 months, that cannot be explained by an alternative diagnosis.[2]World Health Organization. A clinical case definition of post COVID-19 condition by a Delphi consensus. October 2021 [internet publication]. https://www.who.int/publications/i/item/WHO-2019-nCoV-Post_COVID-19_condition-Clinical_case_definition-2021.1 The same definition may also be used for children and adolescents.[3]World Health Organization. Clinical management of COVID-19: living guideline​. August 2023 [internet publication]. https://app.magicapp.org/#/guideline/j1WBYn

The Centers for Disease Control and Prevention endorses the 2024 National Academies of Sciences, Engineering, and Medicine (NASEM) definition: Long COVID, also known as post COVID conditions, is an infection-associated chronic condition that can occur after SARS-CoV-2 infection, the virus that causes COVID-19, 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.[4]Centers for Disease Control and Prevention. COVID-19: clinical overview of long COVID. Feb 2025 [internet publication]. https://www.cdc.gov/covid/hcp/clinical-overview [5]Ely EW, Brown LM, Fineberg HV, et al. Long covid defined. N Engl J Med. 2024 Nov 7;391(18):1746-53. https://pmc.ncbi.nlm.nih.gov/articles/PMC11687645

The UK National Institute for Health and Care Excellence uses the term post-COVID-19 syndrome, and defines this as signs and symptoms that develop during or after an infection consistent with COVID‑19, continue for more than 12 weeks, and are not explained by an alternative diagnosis. Post‑COVID‑19 syndrome may be considered before 12 weeks while the possibility of an alternative underlying disease is also being assessed.[1]National Institute for Health and Care Excellence. COVID-19 rapid guideline: managing the long-term effects of COVID-19. January 2024 [internet publication]. https://www.nice.org.uk/guidance/ng188

Other common synonyms for the condition include post-acute COVID-19, post-acute sequelae of SARS-CoV-2 infection (PASC), post-COVID syndrome, chronic COVID-19, long-haulers syndrome, long-term COVID, and post-COVID condition (PCC).[6]Del Rio C, Malani PN. COVID-19-New Insights on a Rapidly Changing Epidemic. JAMA. 2020 Apr 14;323(14):1339-40. https://www.doi.org/10.1001/jama.2020.3072 http://www.ncbi.nlm.nih.gov/pubmed/32108857?tool=bestpractice.com [7]Greenhalgh T, Knight M, A'Court C, et al. Management of post-acute covid-19 in primary care. BMJ. 2020 Aug 11;370:m3026. https://www.doi.org/10.1136/bmj.m3026 http://www.ncbi.nlm.nih.gov/pubmed/32784198?tool=bestpractice.com [8]Rubin R. As their numbers grow, COVID-19 "long haulers" stump experts. JAMA. 2020 Oct 13;324(14):1381-3. https://jamanetwork.com/journals/jama/fullarticle/2771111 http://www.ncbi.nlm.nih.gov/pubmed/32965460?tool=bestpractice.com

The definition of long COVID will continue to be evaluated as new data emerge.