Long COVID, PCC, and PASC: Understanding the Terminology

Researchers and public health organizations use various terms to describe the persistent and emerging health problems that can follow SARS-CoV-2 infection. The most widely recognized term is long COVID, which originated with patients and has since been adopted in both clinical and research contexts, as it succinctly captures the experience of ongoing symptoms after acute COVID-19.

In formal health communications, the term Post-COVID Conditions (PCC) is often used as an umbrella term for the wide range of ongoing physical, neurological, and multi-system symptoms that continue or develop weeks to months after initial infection. This label is meant to encompass all long-term sequelae of COVID-19. The World Health Organization (WHO) also uses the term post-COVID-19 condition in its clinical case definitions, which highlight symptom persistence beyond the acute phase and the absence of alternative explanations.

Scientific research frequently uses the technical term Post-acute sequelae of SARS-CoV-2 infection (PASC). As a clinical descriptor, PASC refers to the persistent health effects that follow the acute phase of infection and is commonly used in epidemiological studies.

Other terms encountered in both clinical and research settings include post-acute COVID-19, post-acute COVID-19 syndrome, post-COVID syndrome, long-haul COVID, chronic COVID, and long-term effects of COVID.

These labels all refer to the same phenomenon, ongoing health challenges after acute illness, though varying in formality and context. Additionally, they aim to identify and categorize the diverse and often debilitating health outcomes that persist after COVID-19 infection, to support research, and to guide clinical care as understanding of the condition grows.