Chronic Fatigue Syndrome (ME/CFS)

Condition

Myalgic encephalomyelitis (or encephalopathy)/chronic fatigue syndrome (ME/CFS) is a chronic, fluctuating illness causing a wide range of symptoms, the central feature of which is debilitating fatigue worsened by activity and not significantly relieved by rest. NICE is explicit that there currently is no diagnostic test for ME/CFS and it is recognised on clinical grounds alone — it remains a diagnosis of exclusion supported by a characteristic symptom pattern, not a lab result.

Demographics and severity

• Onset typically age 20–40; women affected roughly 2x more often than men.
• NICE grades severity into four bands rather than the old mild/moderate/severe split alone:
  • Mild — mobile and self-caring, can manage light domestic tasks with difficulty; most continue in education/work but often stop other activities to do so.
  • Moderate — reduced mobility, restricted in all activities of daily living (though with peaks and troughs); usually stopped work/education; often need rest periods, typically resting in the afternoon.
  • Severe — unable to carry out most daily activities, reduced or absent ability to do light tasks themselves; may need a wheelchair for mobility, experience prolonged post-exertional malaise, and be housebound or largely confined to bed most of the time.
  • Very severe — unable to carry out any daily activities themselves, completely bed-bound, dependent on carers, and often unable to tolerate light, noise or talking for any length of time.
• Course is variable and unpredictable, with fluctuation and relapse common; spontaneous recovery does occur but is not guaranteed, and children/young people have a better prognosis than adults.

Suspecting and diagnosing ME/CFS

Suspect ME/CFS after 6 weeks of persistent fatigue in adults, or 4 weeks in children and young people (down from this note’s original 6-month framing), when the fatigue:

• is debilitating and worsened by activity, is not caused by excessive cognitive, physical, emotional or social exertion, and is not significantly relieved by rest;

together with post-exertional malaise (PEM) after activity — worsening of symptoms that is often delayed by hours or days, is disproportionate to the activity, and has a prolonged recovery time that may last hours, days, weeks or longer — plus unrefreshing sleep or sleep disturbance, and/or cognitive difficulties (“brain fog”: problems thinking, executive function, memory, processing information, word-finding, or planning/organising).

PEM is now recognised as a core diagnostic feature, not an incidental symptom.

Other supportive features seen clinically: myalgia, arthralgia, headaches, sore throat, tender cervical lymphadenopathy, ~2/3 with a clear preceding viral trigger, and a mild pharyngeal appearance or localised muscle tenderness on examination with otherwise unremarkable findings.

Explain to people with suspected ME/CFS that their diagnosis can only be confirmed after 3 months of persistent symptoms, but that they can return for review earlier if new or worsening symptoms develop.

Investigations

Investigations remain aimed at excluding other causes, not confirming ME/CFS (there is no diagnostic test). NICE specifies: urinalysis for protein, blood and glucose; FBC; U&E; LFT; TFT; ESR or plasma viscosity; CRP; calcium and phosphate; HbA1c; serum ferritin (children/young people); coeliac disease serology; and creatine kinase. Use clinical judgement for additional testing — vitamin D, B12, folate, further serology, or a 9am cortisol — depending on the clinical picture. As a rule: if new symptoms develop, investigate; if no new symptoms, avoid repeated over-investigation.

Referral: refer adults directly to an ME/CFS specialist team to confirm the diagnosis and develop a care and support plan (referral routes and timing vary for children/young people and for severe/very severe presentations).

Management

The single biggest point to get right: fixed graded exercise therapy (GET) is no longer recommended, and CBT is not a means to “push through” symptoms and is not curative.

What NICE says not to do

Do not offer, or advise, any therapy based on physical activity or exercise as a cure for ME/CFS, including generalised physical activity or exercise programmes, or any programme built on fixed incremental increases in the time spent being physically active — i.e. GET, defined by NICE as first establishing a baseline of achievable activity and then making fixed incremental increases regardless of symptom response. Programmes based on deconditioning/exercise- avoidance theories of ME/CFS are also not recommended.

Also: do not offer the Lightning Process, or therapies based on it, to people with ME/CFS; do not offer any medicine or supplement as a cure for ME/CFS (medicines are for symptom control only, and people with ME/CFS may be more intolerant of standard doses, so start low); and there is not enough evidence to support routinely taking vitamin/mineral supplements as a cure.

What NICE recommends instead

Energy management is the central self-management strategy: patient-led, individually tailored, and flexible — activity is never automatically increased on a fixed schedule but adjusted (up, down, or maintained) according to the person’s own symptoms and their PEM pattern. This is not curative, but helps people stay within their energy limits while retaining as much function as possible.

A structured, personalised physical activity/exercise programme may still be offered, but only overseen by an ME/CFS specialist team and only within the energy-management framework above (never as a fixed incremental/GET-style programme, and never advised without specialist oversight).

Rest and sleep, mobility, orthostatic intolerance and pain: manage rest periods and sleep hygiene individually; support physical functioning and mobility (including aids where needed) as part of the care and support plan; medicine for orthostatic intolerance should only be prescribed/overseen by a clinician experienced in it; refer significant pain to specialist pain services and apply relevant NICE neuropathic pain/headache guidance.

CBT: now positioned only as supportive, not curative — NICE states it may help them manage their symptoms but it is not curative. It should be offered to help people manage symptoms, improve functioning and reduce the distress of a chronic illness, and — importantly — a NICE-conformant CBT approach does not assume ME/CFS is caused by “abnormal” illness beliefs/behaviours; it recognises that thoughts, feelings, behaviours and physiology interact with each other.

Diet: encourage adequate fluid intake and a balanced diet; refer to a dietitian if losing/gaining weight unintentionally or on a restrictive diet; consider vitamin D deficiency risk in housebound/bedbound patients.

Flare-ups vs relapse: a flare-up is a worsening of symptoms beyond normal day-to-day variation lasting a few days; a relapse is a sustained, marked exacerbation lasting longer than a flare-up, needing substantial and sustained adjustment of the energy-management plan.

Review in primary care: offer adults with ME/CFS a review of their care and support plan in primary care at least once a year; children and young people should be reviewed at least every 6 months.

Coexisting conditions (e.g. fibromyalgia, IBS, postural orthostatic tachycardia) should be managed alongside ME/CFS according to their own relevant guidance, not left unaddressed.