Chronic fatigue syndrome was first described in the early 1980s, and it affects an estimated two and a half million Americans. For many years, doctors’ tests couldn’t find an explanation for patients’ symptoms, so they were dismissed as “nothing wrong.” But a growing body of research reveals plenty of things going wrong in chronic fatigue syndrome.

“Over the last 35 years, there have been over 9,000 scientific publications that compare people with the illness to healthy people of the same age and sex,” explained Anthony Komaroff, a professor at Harvard Medical School and senior physician at Brigham and Women's Hospital. “And they find a whole variety of abnormalities.”

Anthony Komaroff, Harvard Medical School

Many of those abnormalities involve the brain. There are physical differences in the brain, as well as differences in hormone levels and electrical activity. Some of those brain changes may, in turn, explain differences elsewhere in the body, such as blood pressure or digestion.

Not surprisingly, energy metabolism is also affected in people with chronic fatigue syndrome. Notably, while exercise typically makes energy metabolism more efficient, the opposite is true for people with chronic fatigue syndrome.

Another finding is that the immune system appears to be chronically activated.

“It's as if the immune system were going to war against something, but what that something is hasn't been determined. And it might, in fact, be different from one person to the next,” Komaroff described. “Parts of the immune system appear to be exhausted because they've been chronically activated for so many months and years.”

These differences can help explain symptoms and can provide targets for treatments to alleviate those symptoms. But to develop a treatment – or cure – that actually fixes the underlying problems that lead to chronic fatigue syndrome, researchers need to piece together a chain of cause and effect.

Komaroff says that one leading idea, at the moment, is that inflammation in the brain is important in causing chronic fatigue syndrome.

“There is probably in every patient with this illness a final common pathway that gets triggered in the brain that leads the brain to experience the symptoms of the illness,” Komaroff said.

“What triggers that final common pathway? It appears that in many people - perhaps most - inflammation somewhere in the body, either directly in the brain itself or elsewhere in the body, that sends signals to the brain leads the brain's immune system to get activated.”

Komaroff says that medications or therapies that damp down inflammation could be promising candidates for stopping or reversing chronic fatigue syndrome.

But Komaroff says there’s an even more immediate challenge for many patients with chronic fatigue syndrome – and that’s getting their illness diagnosed.

“Many doctors still don't know that there are over 9,000 studies in the published scientific literature that show that there is something wrong in the body,” Komaroff lamented. “They order their usual tests, the usual tests come back normal, and they say there's nothing wrong.”

Unfortunately, that’s not a problem that is limited to chronic fatigue syndrome.

“Any time a person walks into a doctor's office with an odd collection of symptoms the doctor doesn't recognize it - can't figure it out - there is the possibility that the doctor will not respond in a healthy way, and instead say to the patient ‘There's really nothing wrong with you,’” Komaroff said.

Komaroff says that doctors, and the medical system as a whole, need to trust patients and be willing to do the hard work to figure out what is really wrong. That effort is just beginning to pay off for those with chronic fatigue syndrome.