Mild myalgic encephalomyelitis or chronic fatigue syndrome

Mild myalgic encephalomyelitis or mild chronic fatigue syndrome or mild ME/CFS is a serious neurological disease, and should not be confused with either a mild level of illness, or mild fatigue.

People with mild ME/CFS cannot carry on as normal and are forced to reduce their activities because of the hallmark symptom, post-exertional malaise, which prevents them from engaging in exertion beyond certain thresholds without a significant worsening of symptoms. While the term "mild" is used, mild ME/CFS still entails a substantial level of functional impairment compared to that of a healthy person.

Mild ME/CFS is the lowest level of severity of ME/CFS, which is a serious neurological disease affecting many different bodily systems.

Mild ME/CFS is not

 * it is not another name for unexplained chronic fatigue
 * a symptom caused by another another illness
 * similar to feeling "Tired all the time" (TATT)
 * another name for burnout or exhaustion, or the result of doing too much
 * a lack of fitness, or the result of doing too little
 * persistent sleepiness, although some people need excessive amounts of sleep especially in the first 6 months of falling ill
 * it cannot be cured by willpower, or a positive attitude
 * a brief illness - it is a long term condition
 * Medically unexplained symptoms - there is clear medical evidence of abnormalities not found in any other diseases

NHS definition
Mild ME/CFS

People with mild ME/CFS care for themselves and do some light domestic tasks (sometimes needing support) but may have difficulties with mobility. Most are still working or in education, but to do this they have probably stopped all leisure and social pursuits. They often have reduced hours, take days off and use the weekend to cope with the rest of the week.

The UK's National Health Service definition of mild ME/CFS can be found within the 2021 NICE guidelines.

International Consensus Criteria
Mild Myalgic Encephalomyelitis requires a minimum of a 50% reduction in activity as a direct result of the illness.

Invisible illness
ME/CFS is known as an invisible illness due to the lack of obvious physical signs of illness.

Notable studies

 * 2015, Fatigue in adults with post-infectious fatigue syndrome: a qualitative content analysis -(Full text)