What is chronic fatigue syndrome?

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), or simply chronic fatigue syndrome, is an illness that affects people’s ability to carry out their usual activities. The condition is most often characterized by overwhelming fatigue that doesn’t improve—even with rest.

According to the Institute of Medicine, CFS affects 836,000 to 2.5 million Americans. Additionally, an estimated 84 to 91 percent of people with the condition have not yet been diagnosed.

While researchers don’t know what causes chronic fatigue syndrome, scientists theorize that possible triggers for the illness include viral infections, immune system problems, hormonal imbalances and physical and emotional stress.

Who gets chronic fatigue syndrome?

Anyone can develop chronic fatigue syndrome, but, the condition most commonly affects people between ages 40 and 60. Although children and adolescents can also develop CFS, more teens experience the illness.

According to the Centers for Disease Control and Prevention, scientists estimate that up to 2 in 100 children suffer from CFS.

Women are more likely to be diagnosed with chronic fatigue syndrome than men. Researchers believe this happens because women report their symptoms more often than their male counterparts.

What are the symptoms of chronic fatigue syndrome?

There are three primary, or core, symptoms a person must exhibit to be diagnosed with chronic fatigue syndrome: sleep problems, greatly lowered ability to do activities that were usual before the illness and post-exertional malaise (PEM), a cluster of symptoms involving a loss of stamina and rapid muscle or cognitive fatigue and lasting 24 hours or more. In addition, PEM may cause a worsening of other symptoms.

In addition to these core symptoms, an individual must show signs they’re experiencing problems either with thinking and memory or a worsening of symptoms while standing that improves upon lying down, which is called orthostatic intolerance.

Other common symptoms include:

  • muscle pain and aches
  • joint pain without swelling or redness
  • headaches, either new or worsening
  • tender lymph nodes in the neck or armpits
  • a frequent sore throat
  • digestive issues, including irritable bowel syndrome
  • chills and night sweats
  • allergies and sensitivities to foods, odors, chemicals or noise.

Chronic fatigue syndrome can result in related complications, such as depression, social isolation, lifestyle restrictions and increased work absences.

How is chronic fatigue syndrome diagnosed?

Doctors will ask patients about their personal and family medical history before conducting physical and mental status examinations and ordering blood, urine or other tests.

Next, health care providers ask interview patients to determine whether a person has CFS symptoms.

Patients may also be referred to a specialist in order to rule out other conditions that cause similar symptoms.

How is chronic fatigue syndrome treated?

Although the Food and Drug Administration has not approved any cures or treatments, some symptoms may be managed and treated.

For example, for post-exertional malaise, activity management (also called pacing) can help balance rest and activity to avoid flare-ups.

In addition, doctors might recommend medicine for folks who have trouble sleeping. Some may suggest an over-the-counter sleep aid. If that’s unsuccessful, doctors will usually prescribe sleep medicine. (A sleep specialist may also be helpful if this symptom persists.)

Symptoms made worse upon standing that get better after lying down can be managed by seeing a specialist, increasing fluid and salt intake, and using support stockings. If symptoms don’t improve, doctors will generally prescribe medication.

Memory aids, such as organizers and calendars, can help folks experiencing memory loss. Those with concentration problems may find that stimulant medicines, such as those typically used to treat attention-deficit/hyperactivity disorder (ADHD), can alleviate these issues.

Strategies that don’t involve prescription drugs include professional counseling, following a balanced diet, taking certain nutritional supplements and trying complementary or alternative therapies. Some of these treatments include massage and stress management techniques, such as meditation, muscle relaxation, and homeopathic remedies. Many people may find them to be beneficial, but there is insufficient evidence that any of these treatments really work.

Last Reviewed: February 3, 2020