What is Chronic Fatigue Syndrome?

Exhaustion, Pain, Flu-Like Symptoms

Chronic fatigue syndrome (aka ME/CFS or SEID) is much more than just being tired a lot. People with ME/CFS are so run down that it interferes with their lives and can make it hard to function at all. Some say they have trouble staying on top of their responsibilities at home and on the job, while others are severely disabled and even bedridden. Furthermore, they're not just dealing with extreme fatigue but with a wide range of other symptoms, including flu-like symptoms and chronic pain.

After years of research, experts now suspect that something called central sensitization is at least partially to blame for ME/CFS. They also believe that's what makes it so similar to fibromyalgia, which shares many of the same features.

The CDC says the first credible evidence of a biological basis for this condition came in 2006, when 20 researchers from different specialties each linked the illness with genes involved in the sympathetic nervous system and the HPA axis. These genes control how your body responds to things like injuries and stress.

Many researchers believe at least some cases are caused by an abnormal reaction to common infectious agents. The condition is tentatively linked the the Epstein-Barr virus, enteroviruses, human herpesvirus 6 (HHV-6) and Lyme disease, although studies haven't proved a consistent causal link. However, multiple studies suggest that the immune system may be chronically active in people with ME/CFS, which could at least partially explain the fatigue and lack of energy -- basically, your body thinks it's fighting an infection, whether it is or not, and that takes a lot of energy.

Evidence for immune-system activation includes:

  • High levels of pro-inflammatory cytokines (a cellular messenger in the immune system)
  • Decreased function of natural killer (NK) cells
  • Presence of autoantibodies (antibodies that attack your own tissues)
  • Reduced response of T cells (a type of white blood cells) to specific infectious agents

    Literature on this illness (by different names) dates back to the 1700s. Through the centuries, it's been falsely attributed to various causes and is only now beginning to be better understood by medical science. ME/CFS still goes by many names, including "chronic fatigue and immune dysfunction syndrome" (CFIDS), and "myalgic encephalomyelitis" (ME). Many patients and medical workers want to change the name, believing that the name "chronic fatigue syndrome" itself trivializes the condition and contributes to continued misunderstanding of it.


    Symptoms and their intensity vary from person to person.

    Common symptoms include:

    • Sudden severe fatigue, especially following a flu-like illness
    • Sleep that isn't refreshing
    • Muscle and joint aches without swelling
    • Intense or changing patterns of headaches
    • Sore throat
    • Swollen lymph glands in the neck or armpits
    • Memory problems/inability to concentrate
    • Symptoms have a distict onset

    Other symptoms can include:

    • Dry eyes and mouth
    • Impaired circulation in the hands and feet
    • Visual disturbances
    • Painful menstrual periods

    For fatigue to be considered severe, it must meet the four following criteria:

    1. It's not relieved by sleep or rest
    2. It's not the result of strenuous physical labor
    3. It significantly lowers your ability to function normally in most situations
    4. It gets a lot worse after mental or physical exertion, or after you've been sick

    Learn more: The Monster List of Chronic Fatigue Syndrome Symptoms

    Getting a Diagnosis

    After your doctor has eliminated the possibility that your fatigue and pain are caused by another ailment, it's time to see whether your symptoms fit the criteria for ME/CFS.

    According to the most recent diagnostic guidelines set by the CDC, you must have had fatigue for more than six months that impairs normal activities and cannot be attributed to any identifiable medical or psychological problems.

    Researchers haven't yet discovered the underlying cause of the condition, and so far it's incurable. Only a small percentage of the people who see a doctor for fatigue can be diagnosed with ME/CFS. When a doctor can't find a cause for fatigue but the patient's symptoms don't meet the criteria, a likely diagnosis is idiopathic (of unknown cause) chronic fatigue.

    Learn more: Diagnosing Chronic Fatigue Syndrome

    Treatment Options

    ME/CFS impacts more than a million people in the U.S. Treatment can include prescription or over-the-counter medications to help with specific symptoms, complementary or alternative therapies and emotional support.

    Common drug types are antidepressants; antivirals; allergy medications (antihistamines); nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen (Motrin, Advil) and naproxen (Aleve); and immune-system boosters. Clinical trials suggest that the antiviral drug Ampligen improves the use of oxygen, thereby making it easier for them to exercise. However, the FDA denied the manufacturer's application for approval.

    Also being researched are psychostimulants (including Dexamphetamine, Adderal, Ritalin and Concerta, which may help with memory and concentration problems; D-ribose, which improves cellular function and may help with energy, sleep, mental clarity and pain reduction; and antibiotics, which can help level out the immune system.

    Some medical practitioners recommend dietary changes, herbal or nutritional supplements, homeopathic remedies, yoga and acupuncture. Because ME/CFS can be an extremely stressful condition, and could be made worse by stress, some sufferers benefit from counseling, support groups and stress-reduction techniques.

    Learn more: Treating Chronic Fatigue Syndrome


    Lorusso L, et al. Autoimmunity Review. 2009 Feb;8(4):287-91. Immunological aspects of chronic fatigue syndrome.

    Centers for Disease Control and Prevention. Press Briefing Transcripts: Chronic Fatigue Syndrome, April 2006. Accessed September 2014.

    University of Maryland Medical Center (UMMC). All rights reserved. "Chronic Fatigue Syndrome"

    Continue Reading