What is ME/CFS?

ME/CFS is a long-term medical condition that was first recognised in 1934. It has had many names, has been misunderstood and under researched, but is now receiving more recognition worldwide.

People of all ages, genders and ethnicities can be affected, though 70-80% with ME/CFS are female.

It is a “complex, chronic medical condition affecting multiple body systems”  NICE

This means that people with ME/CFS can experience a wide range of symptoms and they are no longer able to function the way they used to. Simple daily tasks become difficult. People can feel weak, heavy, sore, unbalanced and unable to think straight.

“Everyday life for people with ME/CFS, their family and carers is disrupted and unpredictable. Many people with the condition are unemployed, and less than a fifth work full-time. Approximately 25% have severe disease and are housebound or bedbound.” NICE

ME/CFS Information

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ME/CFS Symptoms

People with ME/CFS can experience a wide range of symptoms because many parts of the body do not function properly.

Terms mean different things to different people, so it is worth learning what they mean in ME/CFS.

‘Debilitating fatigue’ in ME/CFS is not just feeling tired or exhausted. It is worsened by all kinds of activity, is not caused by excessive cognitive, physical, emotional or social exertion, and is not significantly relieved by rest.

Loss of energy is accompanied by feeling unwell:

  • feeling flu-like, especially in the early days of the illness
  • restlessness or feeling ‘wired but tired’
  • low energy or a lack of physical energy to start or finish activities of daily living and the sensation of being ‘physically drained’
  • rapid loss of muscle strength or stamina after starting an activity, causing for example, sudden weakness, clumsiness, lack of coordination, and being unable to repeat physical effort consistently.

Post-exertional malaise (PEM) is the worsening of symptoms that can follow minimal cognitive, physical, emotional or social activity, or activity that could previously be tolerated.

Symptoms can typically worsen 12 to 48 hours after activity and last for days or even weeks, sometimes leading to a relapse. Post-exertional malaise may also be referred to as post-exertional symptom exacerbation (PESE).
Sleep problems include unrefreshing sleep or sleep disturbance (or both), which may mean that:

  • Even after a full night’s sleep, people do not feel refreshed. They wake up exhausted and feeling as if they have not slept at all, no matter how long they were asleep.
  • feeling flu-like and stiff on waking
  • broken or shallow sleep,
  • altered sleep pattern or hypersomnia (excessive sleeping).

Cognitive difficulties (sometimes described as ‘brain fog’) may include:

  • problems finding words or numbers
  • difficulty in speaking
  • slowed responsiveness
  • short-term memory problems
  • and difficulty concentrating or multitasking.

Many people with ME/CFS experience the following symptoms:

  • orthostatic intolerance and autonomic dysfunction, including dizziness, palpitations, fainting, nausea on standing or sitting upright from a reclining position
  • temperature hypersensitivity resulting in profuse sweating, chills, hot flushes, or feeling very cold
  • neuromuscular symptoms, including twitching and myoclonic jerks
  • flu-like symptoms, including sore throat, tender glands, nausea, chills or muscle aches
  • intolerance to alcohol, or to certain foods and chemicals
  • heightened sensory sensitivities, including to light, sound, touch, taste and smell
  • pain, including pain on touch, myalgia, headaches, eye pain, abdominal pain or joint pain without acute redness, swelling or effusion.

Read about key symptoms: Myalgic encephalomyelitis (or encephalopathy)/chronic fatigue syndrome: diagnosis and management, NICE guideline: NG206, 29 October 2021

A wide range of possible symptoms: MEpedia – symptoms

ME and PEM: a video from Norwegian ME Association
Post exertional symptom exacerbation: a video from Long Covid Physio

What causes ME/CFS?

ME/CFS is most likely caused by an infection that triggers long‑lasting changes in the immune system, energy production, and stress‑response systems in people who are genetically vulnerable.

It is often called a multi-system illness because so many systems in the body are affected.

Read a one-page overview: What causes ME/CFS?, from the CDC

New information is constantly being uncovered. Keep up to date with the latest research on the WAMES news blog

History of ME

History of ME: from MEpedia
ME/CFS Scandal Explainer: a video from Broken Battery
The Tangled Story of ME/CFS: a video from Dialogues for a neglected illness

Names

Myalgic Encelphalomyelitis (ME) – the original name
Chronic Fatigue Syndrome (CFS) – a name patients never liked
ME/CFS = a compromise recommended by NICE
ME = the term patients prefer, until a better one is found
Post-Viral Fatigue Syndrome (PVFS) – often used before a diagnosis of ME/CFS