Table 1.

Long COVID definitions in adults

		Duration of symptoms	Previous history	Other criteria
National Institute of Health and Care Excellence (NICE) [3]	Ongoing symptomatic COVID-19	4 to 12 weeks	Acute COVID-19	Persistence of symptoms
	Post COVID-19 syndrome	Over 12 weeks	Acute COVID-19	Persistence of symptoms
Center for Disease Control and Prevention (CDC) [4]		4 weeks or more after the infection	SARS-CoV-2 infection
World Health Organization (WHO) [5]		At least 2 months	Probable or confirmed SARS-CoV-2 infection	- Symptoms presenting 3 months after the onset of COVID - Cannot be explained by an alternative diagnosis - Impact on everyday functioning - Symptoms may continue or develop after the infection - May fluctuate or relapse over time