RT Journal Article T1 Defining Post-COVID Symptoms (Post-Acute COVID, Long COVID, Persistent Post-COVID): An Integrative Classification A1 Fernández De Las Peñas, César A1 Palacios Ceña, Domingo A1 Gómez Mayordomo, Víctor A1 Cuadrado Pérez, María De La Luz A1 Florencio, Lidiane L. AB The pandemic of the coronavirus disease 2019 (COVID-19) has provoked a second pandemic, the “long-haulers”, i.e., individuals presenting with post-COVID symptoms. We propose that to determine the presence of post-COVID symptoms, symptoms should appear after the diagnosis of SARS-CoV-2 infection; however, this situation has some problems due to the fact that not all people infected by SARS-CoV-2 receive such diagnosis. Based on relapsing/remitting nature of post-COVID symptoms, the following integrative classification is proposed: potentially infection related-symptoms (up to 4–5 weeks), acute post-COVID symptoms (from week 5 to week 12), long post-COVID symptoms (from week 12 to week 24), and persistent post-COVID symptoms (lasting more than 24 weeks). The most important topic is to establish the time reference points. The classification also integrates predisposing intrinsic and extrinsic factors and hospitalization data which could promote post-COVID symptoms. The plethora of symptoms affecting multiple systems exhibited by “long-haulers” suggests the presence of different underlying mechanisms. PB MPDI SN 1660-4601 YR 2021 FD 2021-03-05 LK https://hdl.handle.net/20.500.14352/6924 UL https://hdl.handle.net/20.500.14352/6924 LA eng NO Fernández De Las Peñas, C., Palacios Ceña, D., Gómez Mayordomo, V. et al. «Defining Post-COVID Symptoms (Post-Acute COVID, Long COVID, Persistent Post-COVID): An Integrative Classification». International Journal of Environmental Research and Public Health, vol. 18, n.o 5, marzo de 2021, p. 2621. DOI.org (Crossref), https://doi.org/10.3390/ijerph18052621. DS Docta Complutense RD 18 abr 2025