On October 6, the World Health Organization (WHO) released a document containing an official global definition for what many have variously called “long COVID,” “post-COVID syndrome,” and “long-hauler syndrome”. 

What Is the Official Definition?

The document defines what is now called post-COVID-19 condition as occurring “in individuals with a history of probable or confirmed SARS-CoV-2 infection, usually three months from the onset of COVID-19 with symptoms that last for at least two months and cannot be explained by an alternative diagnosis.”

It goes on to list common symptoms like fatigue, shortness of breath, cognitive dysfunction, and “others” (that are included in an appendix attached to the document). 

Another defining factor is that a patient’s symptoms typically impact daily functioning. The symptoms may linger from the initial illness or appear after recovery from the infection. They may also fluctuate, change, and/or recur over time. A separate definition, the document states, may be needed for children.

The WHO also makes clear in the document that this clinical case definition is intended for use in community and healthcare settings to “optimize recognition and care of people experiencing post-COVID-19 condition,” and is likely to change as new evidence comes to light and our understanding of COVID-19 and its consequences evolves. 

Effects of Long COVID

According to Inimary Toby, PhD, an assistant professor of biology at the University of Dallas and a member of the American Physiological Society, there tend to be three primary clusters of symptoms during acute COVID-19 illness:

• Respiratory symptoms, including cough, phlegm, and shortness of breath
• Musculoskeletal symptoms, including muscle and joint pain, headache, and fatigue
• Enteric symptoms, including abdominal pain, vomiting, and diarrhea

Joseph A. Roche, BPT PhD, associate professor of physical therapy at Wayne State University, said that although long COVID resembles myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), a condition that can affect people after viral illnesses, “What makes post-COVID-19 condition more concerning than ME/CFS, is that there is not just physical and mental fatigue, but also persistent and recurrent problems that affect the lungs, heart, blood vessels, and other organs and tissues.” Complications involving heart attack and stroke have also been known to occur.

How Long Should I Expect Long COVID to Last?

No one can accurately predict how long any given person’s post-COVID-19 condition might last, said Roche. Data show that people with SARS still had symptoms at a four-year follow-up. COVID-19 may prove as lengthy or not. According to Toby, the latest estimate is that 10% to 20% of patients will experience long-COVID symptoms for several weeks to several months, but increasing evidence shows some symptoms occurring more than a year later. Roche calls the trend disturbing.

“I have been in touch with patients,” he said, “who had COVID-19 during the first waves of infections and have still not recovered completely.”

How Can I Protect Myself and My Loved Ones?

There is currently no known way to avoid long COVID once you’ve been infected with the SARS-CoV-2 virus, so experts say the best way to avoid long COVID is still to prevent the virus from spreading. Masking, physical distancing, contact tracing, self-quarantine when you’re sick, and vaccination are all steps that you can take to protect yourself and your loved ones from the risk of contracting COVID-19 and, by extension, long COVID. 

*Schimelpfening, N. (2021, Oct. 12). Long COVID Now Has a Formal Definition from the WHO: What to Know. Healthline. https://www.healthline.com/health-news/long-covid-now-has-a-formal-definition-from-the-who-what-to-know#1 

Much about the novel coronavirus, i.e., COVID-19, is still not fully understood. As research progresses and our knowledge of the virus increases, information can change rapidly. We strive to update all of our articles as quickly as possible, but there may occasionally be some lag between scientific developments and our revisions.