Chronic fatigue syndrome (CFS), or myalgic encephalomyelitis (ME), is an overlooked medical condition that affects about 1.5 million Americans. The COVID-19 pandemic has shed new light on the complicated disorder, as researchers have found that many post-COVID patients suffered from similar symptoms.

Some symptoms of chronic fatigue syndrome include severe and constant tiredness, problems with memory or concentration, sickness symptoms, sore throat or headaches after physical or social activities, unexplainable muscle and joint pain, and the inability to get a good night's sleep or rest after physical or mental exercise. It can last for at least six months, according to the Mayo Clinic.

Chronic fatigue syndrome extends beyond the psychological symptoms often associated with depression and is a seriously debilitating chronic illness that manifests more physically. There are several conditions and illnesses that could present with similar symptoms as chronic fatigue syndrome, which makes it hard to diagnose.

“There is this presumption that perhaps it's just depression or anxiety, or perhaps it's the pandemic or the state of the world, but people know when there's something wrong with them,” Jaime Seltzer, director of scientific and medical outreach at #MEAction, told NPR.

There are many similarities between the symptoms of long COVID and chronic fatigue syndrome.

The disability community, including those with chronic fatigue syndrome pre-pandemic, were “some of the first to raise alarm bells that this was going to be a mass disabling event. We were looking at symptoms of long COVID and saying there are going to be a boatload of people with CFS/ME [chronic fatigue syndrome],” Robert Sklans of the #MEAction Network told NorthJersey.com.

While the long-term effects of COVID remain largely unknown — the pandemic is only entering its third year — it is estimated that 1 in 10 infections may get chronic fatigue syndrome. With nearly 78 million cases recorded in the U.S., 7.8 million Americans could face chronic fatigue syndrome.

The number could even triple given the high volume of those in the U.S. who have had the virus and experience long COVID symptoms, according to experts.

There is not a wealth of resources on the federal and state level dedicated to addressing chronic fatigue syndrome. According to the National Institutes of Health, the estimated funding budget for chronic fatigue syndrome for 2022 is $16 million.

“People with chronic complex disease have been living with this for decades. Researchers have been studying this for decades. We definitely need to make use of the path that we've beaten down over time and start basing our hypotheses off of what we've seen in these diseases with other labels,” Seltzer told NPR.