As many as 2.5 million Americans have a condition known as chronic fatigue syndrome, in which they are often both mentally and physically exhausted.

But experts at the Institute of Medicine (IOM) say the term “chronic fatigue syndrome” (CFS) doesn’t do the condition justice and can understate how much it affects a person’s daily life.

That’s why, in a report released Tuesday, an IOM volunteer committee recommended the condition be called systemic exertion intolerance disease (SEID).

“Several studies have shown that the term ‘chronic fatigue syndrome’ affects patients’ perceptions of their illness as well as the reactions of others, including medical personnel, family members, and colleagues. This label can trivialize the seriousness of the condition and promote misunderstanding of the illness,” the IOM report states. “This new name captures a central characteristic of this disease — the fact that exertion of any sort (physical, cognitive, or emotional) — can adversely affect patients in many organ systems and in many aspects of their lives.”

The same condition has previously been called “myalgic encephalomyelitis,” a name that signifies muscle pain and brain inflammation. Researchers noted a lack of evidence to support brain inflammation as a symptom, as well as the fact that muscle pain isn’t a core symptom of the disease.

Read More: What Is Chronic Fatigue Syndrome? »

The IOM researchers also identified CFS as existing simultaneously with other life-altering conditions, including fibromyalgia, depression, migraines, allergies, and irritable bowel syndrome.

The new report was requested by the Department of Health and Human Services, the National Institutes of Health, the Agency for Healthcare Research and Quality, the Centers for Disease Control and Prevention, the Food and Drug Administration, and the Social Security Administration.

New Diagnostic Criteria for SEID

Doctors don’t know the full scope of CFS or SEID because up to 91 percent of people affected by it have not yet been diagnosed. Some doctors dismiss patients with CFS symptoms because they believe the condition is “all in their heads.”

Without proper treatment, the condition can affect the U.S. economy through lost productivity and medical costs by as much as $24 billion a year.

The IOM’s Committee on Diagnostic Criteria for ME/CFS suggested that the diagnostic guidelines for SEID be changed to reflect available research on the condition.

Read More: Scientists Find Physical Markers of Chronic Fatigue Syndrome »

Diagnostic criteria for the disease formerly known as chronic fatigue syndrome require the patient to have three symptoms:

  • For a period longer than six months, a patient experiences a “substantial reduction or impairment in the ability to engage in pre-illness levels of occupational, educational, social, or personal activities…” provided it is not due to ongoing excessive exertion and not alleviated by rest.”
  • “Post-exertional malaise,” or a period of intense exhaustion following a period of physical activity
  • Lack of refreshing sleep

The patient must also experience either cognitive impairment or orthostatic intolerance.

Orthostatic intolerance, which affects up to 97 percent of people with chronic fatigue, is a collection of symptoms that occur when a person stands upright. They are alleviated when the person sits down. Symptoms can include fatigue, lightheadedness, weakness, sweating, and anxiety.

The IOS hopes the new criteria will provide better education about the disease and improve care for patients.

While there’s no known cause of chronic fatigue, the report states symptoms may begin with an infection or “immunization, anesthetics, physical trauma, exposure to environmental pollutants, chemicals, and heavy metals and, rarely, blood transfusions.”

More research on the condition is essential, the committee noted.

“Remarkably little research funding has been made available to study the etiology, pathophysiology, and effective treatment of this disease, especially given the number of people afflicted,” a summary of the report states. “Thus, the committee was unable to define subgroups of patients or even to clearly define the natural history of the disease.”

Educating Doctors Remains a Challenge

One of the hardest-fought battles for people suffering from chronic fatigue is receiving the correct diagnosis.

The IOS panel noted that less than a third of medical schools cover the condition in their curricula and less than half of medical textbooks include it.

"Seeking and receiving a diagnosis can be a frustrating process for several reasons, including skepticism of health care providers about the serious nature of ME/CFS and the misconception that it is a psychogenic illness or even a figment of the patient’s imagination," states the report.

Too often, chronic fatigue is identified as simple exhaustion, which can lead to delayed diagnosis or misdiagnosis, the report states.

Read more: Why Liver Extract Isn’t Used Much Anymore as a Treatment »