Long COVID

Long COVID
Other namesLong-haul COVID, post-COVID-19 syndrome, post-COVID-19 condition, post-acute sequelae of COVID-19 (PASC), chronic COVID syndrome[1]
SymptomsHighly varied, including post-exertional malaise (symptoms worsen with effort), fatigue, muscle pain, shortness of breath, chest pain and cognitive dysfunction ("brain fog")[2]
DurationWeeks to years, possibly lifelong[3]
CausesCOVID-19 infection
Risk factorsFemale sex, age, obesity, asthma, more severe COVID-19 infection[4]
Frequency50–70% of hospitalised COVID-19 cases, 10–30% of non-hospitalised cases, and 10–12% of vaccinated cases[3]

Long COVID or long-haul COVID is a group of health problems persisting or developing after an initial period of COVID-19 infection. Symptoms can last weeks, months or years and are often debilitating.[3] The World Health Organization defines long COVID as starting three months after the initial COVID-19 infection, but other agencies define it as starting at four weeks after the initial infection.[2]

Long COVID is characterised by a large number of symptoms that sometimes disappear and then reappear. Commonly reported symptoms of long COVID are fatigue, memory problems, shortness of breath, and sleep disorder.[5][4][6] Several other symptoms, including headaches, mental health issues, initial loss of smell or taste, muscle weakness, fever, and cognitive dysfunction may also present.[5][6] Symptoms often get worse after mental or physical effort, a process called post-exertional malaise.[5] There is a large overlap in symptoms with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).[2]

The causes of long COVID are not yet fully understood. Hypotheses include lasting damage to organs and blood vessels, problems with blood clotting, neurological dysfunction, persistent virus or a reactivation of latent viruses and autoimmunity.[3] Diagnosis of long COVID is based on (suspected or confirmed) COVID-19 infection or symptoms—and by excluding alternative diagnoses.[7][8]

As of 2024, the prevalence of long COVID is estimated to be about 6-7% in adults, and about 1% in children.[9] Prevalence is less after vaccination.[10] Risk factors are higher age, female sex, having asthma, and a more severe initial COVID-19 infection.[4] As of 2023, there are no validated effective treatments.[3][5] Management of long COVID depends on symptoms. Rest is recommended for fatigue and pacing for post-exertional malaise. People with severe symptoms or those who were in intensive care may require care from a team of specialists.[11] Most people with symptoms at 4 weeks recover by 12 weeks. Recovery is slower (or plateaus) for those still ill at 12 weeks.[11] For a subset of people, for instance those meeting the criteria for ME/CFS, symptoms are expected to be lifelong.[3]

Globally, over 400 million people have experienced long COVID. Long COVID may be responsible for a loss of 1% of the world's gross domestic product.[9]

  1. ^ Cite error: The named reference defnLancet was invoked but never defined (see the help page).
  2. ^ a b c Cite error: The named reference pmid37433988 was invoked but never defined (see the help page).
  3. ^ a b c d e f Davis HE, McCorkell L, Vogel JM, Topol EJ (March 2023). "Long COVID: major findings, mechanisms and recommendations". Nature Reviews. Microbiology. 21 (3): 133–146. doi:10.1038/s41579-022-00846-2. PMC 9839201. PMID 36639608.
  4. ^ a b c Chen C, Haupert SR, Zimmermann L, Shi X, Fritsche LG, Mukherjee B (November 2022). "Global Prevalence of Post-Coronavirus Disease 2019 (COVID-19) Condition or Long COVID: A Meta-Analysis and Systematic Review". The Journal of Infectious Diseases. 226 (9): 1593–1607. doi:10.1093/infdis/jiac136. PMC 9047189. PMID 35429399.
  5. ^ a b c d "Long COVID or post-COVID conditions". Centers for Disease Control and Prevention, US Department of Health and Human Services. 20 July 2023. Archived from the original on 14 January 2022. Retrieved 23 July 2023.
  6. ^ a b Cite error: The named reference pmid35124265 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Centers for Disease Control and Prevention_2020 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference pmid37182545 was invoked but never defined (see the help page).
  9. ^ a b Al-Aly Z, Davis H, McCorkell L, Soares L, Wulf-Hanson S, Iwasaki A, et al. (August 2024). "Long COVID science, research and policy". Nature Medicine. 30 (8): 2148–2164. doi:10.1038/s41591-024-03173-6. PMID 39122965.
  10. ^ Byambasuren O, Stehlik P, Clark J, Alcorn K, Glasziou P (2023). "Effect of covid-19 vaccination on long covid: systematic review". BMJ Medicine. 2 (1): e000385. doi:10.1136/bmjmed-2022-000385. PMC 9978692. PMID 36936268.
  11. ^ a b Cite error: The named reference pmid36137612 was invoked but never defined (see the help page).