What Long COVID investigators can learn from four decades of ME/CFS research

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a condition that affects different parts of the body, including the brain, the immune system, and the autonomic nervous system, which controls things like heart rate and blood pressure. Many people with Long COVID experience similar symptoms to people with ME/CFS, like feeling more tired after physical or mental effort, which is called post-exertional malaise (PEM). 

This paper summarizes how researchers can use what they have learned about ME/CFS over the past 4 decades to better understand Long COVID. Researchers have made progress in explaining and categorizing known ME/CFS symptoms and findings, coming up with new ways to test for the illness and developing more reliable and standardized assessments (tests) researchers can use. These assessments check how well a person’s body and mind are working. By building on this existing research, RECOVER scientists hope to help other researchers better define and diagnose Long COVID, determine whether someone with Long COVID is likely to get better, get worse, or stay about the same, and identify treatments that could be studied in future clinical trials. This existing research can also help scientists create specific testing tools to help them get consistent information no matter where the test is done.