Who Has Chronic Fatigue Syndrome in the U.S.?

New research pegs the recent prevalence of what’s often called chronic fatigue syndrome at about 1% among U.S. adults, with women, people in more rural communities and those with lower incomes more likely to have the debilitating condition.

Myalgic encephalomyelitis/chronic fatigue syndrome, or ME/CFS, can limit a person’s ability to do routine activities and features overwhelming fatigue that is not remedied by rest, according to the Centers for Disease Control and Prevention. The illness can get worse after exertion, and other symptoms can include dizziness and problems concentrating. While an infection or other event may precede symptoms, the exact cause of the disorder remains unknown.

In the U.S. overall, an estimated 1.3% of adults had ME/CFS in 2021-2022, according to an analysis released Friday by the CDC’s National Center for Health Statistics. The study – based on survey respondents’ answers to whether they’d ever been diagnosed with myalgic encephalomyelitis or chronic fatigue syndrome, and whether they still had such a condition when interviewed – found a greater percentage of ME/CFS cases among women, at 1.7% compared with 0.9% of men.

The study found ME/CFS was most common in adults between the ages of 50 and 59, as well as those 60 to 69 years old, with rates of 2% and 2.1%, respectively. Less than 1% of adults between 18 and 39 years old had ME/CFS, along with 1.4% of those 70 and older.

Among racial and ethnic groups, 1.5% of white adults had ME/CFS, according to the study, along with 1.2% of Black individuals, 0.8% of Hispanics and 0.7% of Asians.

The study additionally found that the likelihood of having ME/CFS decreased as the level of reported family income increased. The prevalence of ME/CFS among adults with family incomes at or above 200% of the federal poverty level was 1.1%, with the rate rising to 1.7% among those with incomes between 100% and 199% of the FPL. Adults with family incomes under 100% of the federal poverty level had the highest percentage of ME/CFS cases at 2%.

Greater shares of ME/CFS cases also were found as communities grew more rural. For example, 1.9% of adults in nonmetropolitan areas had ME/CFS compared with 1% of adults in large central metropolitan areas.

Overall, 1.3% of adults with ME/CFS amounts to 3.3 million people, according to the CDC. But the true prevalence could be higher, as experts have said the overwhelming majority of ME/CFS cases are not diagnosed, and there is no definitive lab test to do so.

Akiko Iwasaki, a professor of immunobiology at Yale University who studies long COVID and has received funding to search for a biomarker for ME/CFS, said in an October article from the school that up to half of people with long COVID will get ME/CFS.

“Long COVID has put a spotlight on existing diseases such as ME/CFS and chronic Lyme disease, which have been traditionally and historically ignored until very recently,” Iwasaki said. “Long COVID has taught the world that these diseases are real, and we need to study them.”