Quick Facts About Chronic Fatigue Syndrome

Just the Basics!

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Chronic fatigue syndrome's defining characteristic is a persistent deep fatigue, similar to what other people feel when they're seriously ill or sleep deprived. In people with chronic fatigue syndrome, however, sleep doesn't relieve fatigue as it does in healthy people.

People with chronic fatigue syndrome also have other symptoms, including severe pain, cognitive problems such as memory loss and confusion, and post-exertional malaise.

Post-exertional malaise causes intense fatigue, pain and muscle weakness for up to 48 hours following exercise or other forms of exertion.

Other symptoms include:

  • pain in joints without swelling or redness
  • achy or weak muscles 
  • persistent sore throat
  • headaches
  • tender lymph nodes
  • persistent low-grade fever or low body temperature
  • chronic cough
  • nausea
  • recurrent flu-like illness

Things like injury, illness, and stress (emotional or physical) can make symptoms worse. Some people have specific triggers (things that increase symptoms), such as foods or chemicals.

People with chronic fatigue syndrome also frequently have coexisting conditions, including fibromyalgia, irritable bowel syndrome, myofascial pain syndrome and multiple chemical sensitivity.

People from every culture and socioeconomic level get chronic fatigue syndrome. It's most common in women, but men and children can come down with it as well.

Chronic fatigue syndrome, by different names, dates back to the 1700s. Throughout the centuries, it's been falsely attributed to various causes and is only now beginning to be understood by medical science. When it broke into the public consciousness in the 1980s, it was given the derogatory name "yuppie flu," because it often seemed to strike young professional people.

Since then, this association has been debunked and we know that people of all personality types and lifestyles can develop this illness.

More than one-million people in the U.S. are known to have chronic fatigue syndrome, but some experts and advocates estimate that many people are undiagnosed and that the number is actually much higher.

Many people with chronic fatigue syndrome are too disabled to work.

The Social Security Administration does recognize chronic fatigue syndrome as a potentially disabling condition. However, having a disability claim approved is a long and difficult process that can be complicated by the ambiguous nature of chronic fatigue syndrome symptoms and the lack of a diagnostic test.

Chronic fatigue syndrome goes by several names, including chronic fatigue and immune dysfunction syndrome (CFIDS), myalgic encephalomyelitis (ME), ME/CFS, and systemic exertion intolerance disease (SEID).

Diagnosing Chronic Fatigue Syndrome

So far, no test can accurately diagnose chronic fatigue syndrome. Doctors need to rule out numerous conditions with similar symptoms before diagnosing it. This is called a diagnosis of exclusion.

Diagnostic criteria include unexplained, persistent fatigue that's lasted for at least six months, and at least four of several other symptoms, including impaired memory or concentration, post-exertional malaise, unrefreshing sleep, muscle pain and others.

Treating Chronic Fatigue Syndrome

The FDA has yet to approve any drugs for chronic fatigue syndrome.

No medical specialty has "claimed" this disease, which can make it difficult to find a doctor knowledgeable about diagnosing and treating it.

People with chronic fatigue syndrome sometimes see massage therapists, chiropractors, physical therapists and other complementary and alternative-medicine practitioners. They may also see a psychiatrist or psychologist to deal with the difficulties of a debilitating condition and possibly for depression.

Depression is common in people with chronic fatigue syndrome, as it is in debilitating pain conditions overall.

Chronic fatigue syndrome, however, is not a psychiatric condition.

What Causes Chronic Fatigue Syndrome?

Researchers don't yet know the exact cause of chronic fatigue syndrome, but many experts now believe it's triggered by genetic mutations combined with exposure to certain viruses or toxins.

Several viruses and other infectious agents have been investigated for links to this condition. Some of them have been proven to not be related, while others have a less certain relationship. Some doctors and researchers believe a handful of pathogens—including Epstein-Barr virus, HHV-6, Lyme disease, and enterovirus—do play a role in some cases.

Even though it has "syndrome" in its most commonly used name, a 2015 report by the U.S. Institute of Medicine elevated it to an official disease when it suggested the name SEID.

Some researchers believe that there have been outbreaks of chronic fatigue syndrome, but other say we have insufficient evidence to prove any such outbreaks.


Centers for Disease Control and Prevention, May 3 2006 "Diagnosing CFS" and "Possible Causes"