Myalgic Encephalomyelitis ("Chronic Fatigue Syndrome")

Myalgic Encephalomyelitis (ME), commonly referred to as chronic fatigue syndrome or ME/CFS, is a widely misunderstood disease. The purpose of this webpage is to provide clear and correct information on what is known about ME today.

People with ME can experience a wide range of symptoms and levels of severity. If you think you or a loved one may have ME, please see the resources at the bottom of this webpage.

What is ME?

Myalgic Encephalomyelitis (my*al*gic + en*ceph*a*lo*my*eli*tis) (ME), commonly referred to as chronic fatigue syndrome, is a serious, debilitating, chronic disease that affects multiple body systems, including the nervous system, the immune system, and the body's production of energy. Experts do not yet know the exact cause of ME, but many people start feeling the symptoms of ME after contracting a viral or other type of infection, or following surgery, physical trauma, or a change in hormonal status. It is possible that the symptoms of ME result from an abnormal response by the immune system, most often to an infection. This can impact the brain and other systems of the body. What is known is that ME is not a psychiatric disorder and it is not caused by a lack of exercise, contrary to common belief.

"My illness is excruciating and difficult to cope with. It takes over your entire life and causes more suffering than I can describe."

Laura Hillenbrand (in The Wall Street Journal), author of Seabiscuit and Unbroken, person with ME since 1987

What are the Symptoms?

The most recognizable symptom of ME is post-exertional malaise (PEM), experienced by all people with ME. This symptom is often described as a "crash" in physical and/or mental energy following even a small amount of activity. People with ME have described PEM as experiencing "the worst flu imaginable," feeling like, "my cells are dying," and "having my life force drained out of me." When people experience PEM, any or all of their symptoms – pain, problems thinking or sleeping, sore throat, headaches, dizziness – may worsen and they may need bedrest for days, weeks or even longer to return to how they felt before the "crash." For some people with ME, something as simple as brushing their teeth, eating, or reading email can cause PEM. In some cases, people do not return to how they felt before the "crash."

Imagine the body's energy level as a battery on a cell phone. Usually, when you plug in a cell phone overnight, the battery is fully charged in the morning, much like the way most people feel after a good night's sleep – fully recharged. The body of a person with ME is like a cell phone with an old battery that can never be fully recharged. Even after hours of sleeping, they still may not have enough energy to do their daily activities.

In addition to PEM, people with ME experience a range of other bodily symptoms that can be severe and impact their daily functioning. The primary symptoms include:

  • Post-exertional malaise (a worsening of any or all symptoms, following even small amounts of mental or physical activity)
  • Extreme exhaustion
  • Confusion and slowed thinking (often referred to as "brain fog")
  • Non-restorative sleep (feeling unrefreshed after sleeping)
  • Dizziness/lightheadedness and racing heart (and other symptoms of orthostatic intolerance)
  • Tender lymph nodes and sore throat
  • Muscle and joint pain, headaches
  • Sensitivities to light, sound, and chemicals
  • Difficulty regulating body temperature (feeling overheated or chilled)
  • Extreme thirst
  • Gastrointestinal disturbances, such as nausea, bloating, diarrhea and constipation

People with ME may appear to be in good physical health and the common blood tests ordered by medical providers don't show anything out of the ordinary. But that does not mean they are not sick. Most adults with ME are unable to work either full or part time and children may either not be able to attend school or require a lot of help with school. One out of four people with ME are housebound or bedbound, and three out of four are housebound or bedbound on their worst days. The most severely affected people with ME need around the clock care.

Who gets ME?

Anybody can get ME. It is estimated that at least one million Americans have ME. ME is more common in women than men, and affects people of all racial, ethnic, and socioeconomic backgrounds. It can also impact adolescents and children younger than 10. The exact prevalence of ME is difficult to determine since most medical providers don't recognize it.

How is ME Diagnosed?

Since the medical community does not have a test to prove that someone has ME, it can be challenging to diagnose and may take some time to do so. Most people with ME struggle for years to get a correct diagnosis, and as many as 90 percent of people with ME are not diagnosed, are misdiagnosed with another disease, or are told they are not sick at all.

ME may present abruptly, most often following an infection but also sometimes following a surgical procedure (such as dental work); or after a large hormonal shift (such as pregnancy or menopause). It may also develop more gradually. Adults typically experience worsening post-exertional malaise (PEM), unrefreshing sleep, cognitive problems and/or orthostatic intolerance, in addition to any of the other symptoms in the list above. Teens and children most often experience PEM, trouble concentrating, unrefreshing or disturbed sleep, pain, dizziness, near fainting, periods of bloating and constipation, problems regulating temperature, and other symptoms.

In 2015, the National Academy of Medicine published new diagnostic criteria for ME, which require the presence of the following:substantial impairment in activity that lasts six months or more and is accompanied by fatigue, post-exertional malaise (PEM), unrefreshing sleep, and either cognitive impairment or orthostatic intolerance.

People with ME may have one or more additional diseases (comorbidities). For example, many people with ME also have fibromyalgia (widespread muscle pain and unrefreshing sleep), postural orthostatic tachycardia syndrome (POTS, increased heart rate upon standing), and/or gastroparesis/irritable bowel syndrome (bloating and constipation). They may also experience secondary depression, Ehler's Danlos Syndrome (hyperextensibility disorder) and mast cell disorders (hives or allergic issues). It's important to diagnose these other illnesses as they should also be treated.

How is ME Treated?

Although cognitive behavior therapy (CBT) and graded exercise therapy (GET) were once recommended to treat patients with ME, these interventions assume that patients are afraid to exercise and thus become out of shape (deconditioned). But these conclusions are based on studies that included patients with other fatiguing conditions. The recommendations to use CBT and GET to treat ME have caused more harm than good for people with ME and have been eliminated from the Centers for Disease Control and Prevention (CDC) website.

Currently, there are no FDA-approved treatments specifically for ME. Among suggested treatments are "pacing", which can help people with ME avoid crashes by matching their level of activity to their limited amount of available energy; use of sleep aids and medications; anti-inflammatory medications and muscle relaxants; and treatments for pain. People with ME can be sensitive to medications so it is recommended to start at low doses.

In addition to prescribing treatments, health care providers can help people with ME apply for disability, obtain assistive devices such as wheelchairs, and receive accommodations in the workplace and at school.


Compiled below is a list of links to resources for adults and children with ME, their caregivers, clinicians and other professionals.

1. Resources for Medical Providers, People with ME and their Caregivers:

Applying for Social Security:

2. Other Resources for Medical Providers and Researchers

Research Centers

3. Other Resources for People with ME and their Caregivers

The organizations listed below may serve as points of contact for support and finding medical providers who specialize in treating ME.


#MEAction is an international network of patients fighting for health equality for Myalgic Encephalomyelitis (ME). The mission is to grow and mobilize a community of patients and allies to be strong and effective advocates for people with ME and related conditions.

Solve ME/CFS Initiative

The Solve ME/CFS Initiative (SMCI) is a non-profit disease organization that works to accelerate the discovery of safe and effective treatments, strives for an aggressive expansion of funding for research that will lead to a cure and seeks to engage the entire ME/CFS community in research.


The Massachusetts CFIDS/ME & FM Association, a 501(c)3 founded in 1985, exists to meet the needs of patients with CFIDS (Chronic Fatigue and Immune Dysfunction Syndrome, also known as Chronic Fatigue Syndrome), ME (Myalgic Encephalomyelitis) or FM (Fibromyalgia), their families and loved ones.

Other potentially useful resources include: