What ME/CFS is
Myalgic encephalomyelitis / chronic fatigue syndrome (ME/CFS) is a long-term, multi-system condition characterised by debilitating fatigue, post-exertional malaise, unrefreshing sleep and cognitive difficulty. It is recognised by the NHS and covered by NICE NG206, which replaced the older 2007 guidance in October 2021.
The four core symptoms (NG206)
NG206 says ME/CFS should be suspected when all four of these features are present and have persisted for at least 6 weeks in adults (4 weeks in children):
- Debilitating fatigue that is worsened by activity, not caused by excessive exertion, and not significantly relieved by rest.
- Post-exertional malaise (PEM) — a worsening of symptoms after physical, cognitive, emotional or social activity that would have been tolerated before, often delayed by hours or days and disproportionate to the activity.
- Unrefreshing sleep or sleep disturbance (or both).
- Cognitive difficulties — problems with thinking, memory, attention or word-finding ("brain fog").
The diagnosis is confirmed at 3 months if the four features persist and other causes have been considered.
The UK NHS pathway (NG206)
- GP appointment focused on the four core features, onset, and how symptoms have changed with activity.
- Examination and a panel of bloods to rule out other causes (see below).
- At 6 weeks: GP should suspect ME/CFS, give energy management advice, and refer to a specialist ME/CFS service if available.
- At 3 months: GP or specialist confirms the diagnosis if criteria are still met.
- Care and support plan covering energy management, symptom-specific support, and access to services like physiotherapy, OT, and dietetics — without GET.
Tests that rule other things out
- FBC, U&E, LFTs, bone profile.
- ESR and CRP (inflammation).
- TFTs (thyroid).
- HbA1c (diabetes).
- Vitamin D, B12, ferritin, folate.
- Coeliac screen.
- Urinalysis.
- Consideration of further tests (e.g. cortisol, ANA) if clinically indicated.
Normal bloods do not rule out ME/CFS — they are expected. The diagnosis is clinical.
What should NOT be offered
NG206 is explicit on a few points that matter:
- Graded exercise therapy (GET) should not be offered. Any fixed incremental exercise programme based on the assumption that ME/CFS is caused by deconditioning is not in line with current NHS guidance.
- The Lightning Process should not be offered.
- CBT may be offered for symptom management or comorbid distress, but not as a cure or as treatment for the underlying condition.
What to ask your GP
- For your bloods to be reviewed against the list above.
- To consider ME/CFS under NICE NG206, naming the four core symptoms — especially PEM.
- For a referral to a specialist ME/CFS service if one is available locally.
- For a written care and support plan covering energy management and pacing.
- Confirmation in writing that GET will not be recommended, in line with NG206.
If your GP won't engage or is still recommending graded exercise, a formal letter naming NG206 and the four core symptoms is usually what unlocks the conversation. Finally Seen writes that letter for you.
Frequently asked questions
›What's the difference between ME and CFS?
In UK clinical guidance they're treated as the same condition: myalgic encephalomyelitis (ME) / chronic fatigue syndrome (CFS). NICE NG206 uses the combined term ME/CFS throughout.
›How long do symptoms need to last for a diagnosis?
Under NG206, ME/CFS should be suspected after 6 weeks of symptoms in adults (4 weeks in children) and confirmed at 3 months if the four core features persist and other causes have been excluded.
›Is graded exercise therapy (GET) still recommended?
No. NICE NG206 explicitly says graded exercise therapy should NOT be offered to people with ME/CFS. Any GP or clinic still recommending GET is working from withdrawn guidance.
›Do I have to see a specialist?
NG206 says the diagnosis can be confirmed by a GP at 3 months, and referral to a specialist ME/CFS service should be offered. In practice many areas have very limited specialist services, so a GP-confirmed diagnosis under NG206 is often the realistic route.
›What's PEM and why does it matter?
Post-exertional malaise — a worsening of symptoms (often delayed by 12–48 hours) after physical, cognitive or emotional activity that would previously have been tolerated. PEM is one of the four core diagnostic features in NG206 and is what distinguishes ME/CFS from ordinary fatigue.