ME/CFS (chronic fatigue syndrome)
Myalgic encephalomyelitis/chronic fatigue syndrome is a long-term illness where even small efforts can trigger a crash a day or two later. It is real and physical. It is not laziness, deconditioning or “just tiredness”, and it is not your fault.
What it is
- A substantial drop in what you can do, lasting more than 6 months, with fatigue that rest doesn’t fix.
- Post-exertional malaise (PEM): symptoms flare after physical, mental or emotional effort, often 12 to 48 hours later, and can last days. This is the hallmark.
- Unrefreshing sleep, plus brain fog (memory, concentration) or feeling worse when upright (orthostatic intolerance).
- Often starts after an infection, such as glandular fever or COVID-19. Long COVID can look very similar.
- It ranges from mild (working with adjustments) to very severe (bed-bound, sensitive to light and sound).
It’s real: what the body shows
- A crash you can measure. On two exercise tests a day apart, people with ME/CFS do worse on day 2, while healthy and deconditioned people don’t (Snell 2013).
- Less blood to the brain when upright. On a tilt table, about 9 in 10 people with ME/CFS had an abnormal drop in brain blood flow, even with a normal heart rate and blood pressure (van Campen 2020).
- Immune, nerve and metabolic changes. A detailed 2024 US National Institutes of Health study found differences in immune cells, the autonomic nervous system and brain activity during effort (Walitt 2024).
- It is recognised as a neurological illness by the World Health Organization’s disease classification.
- No single blood test diagnoses it yet. That reflects the limits of today’s tests, not the reality of the illness.
How it’s diagnosed
- By the pattern of symptoms over time, especially PEM, after other causes are checked.
- Usual tests: full blood count, iron, thyroid, kidney and liver tests, blood sugar, coeliac screen, inflammation markers, and others guided by your story.
- A simple 10-minute stand test can pick up POTS or low blood pressure on standing, which are common and treatable.
What helps
- Pacing (energy management): plan activity within your energy envelope, rest before you crash, and break tasks up. A heart-rate monitor helps some people stay under their limit.
- Treat what can be treated: orthostatic symptoms (fluids, salt if safe, compression), sleep problems, pain, headaches, and low mood or anxiety if present.
- Support: occupational therapy for aids and home changes, workplace or study adjustments, and carer support.
- Severe ME/CFS: a quiet, dim room, minimal visits and planned care at home.
Save your energy and money
- Graded exercise therapy (GET): no longer recommended. The UK’s NICE guideline (2021) advises against fixed increases in exercise because they can make people worse.
- CBT as a cure: it can help with coping, like in any long illness, but it does not treat the illness itself.
- Rituximab: a large trial found it didn’t help (Fluge 2019).
- Expensive “cures” and unproven drips, detoxes and mail-order tests.
Being heard
- Bring a one-page summary: when it started, your PEM pattern, a typical good and bad day, and what you’ve tried.
- Ask: “Could this be ME/CFS or POTS?” and “What else have we ruled out?”
- Keep a symptom and activity diary for 2 weeks before appointments.
- You can ask for a second opinion, a longer appointment, or a home or telehealth visit if travel causes crashes.
See your GP if
- New symptoms that don’t fit, such as weight loss, fevers, night sweats, or new weakness or numbness.
- Fainting, chest pain or a racing heart.
- Low mood or thoughts of self-harm: call Lifeline on 13 11 14, or 000 in an emergency.
Common questions
What is post-exertional malaise?
A flare of symptoms after physical, mental or emotional effort, often starting 12 to 48 hours later and lasting days or longer. It is the key feature of ME/CFS and the reason pacing matters.
Is ME/CFS psychological?
No. It is a physical illness with measurable changes in exercise capacity, blood flow, the immune system and the nervous system. Mental health support can help, as with any long illness, but it isn’t the cause or the cure.
Should I exercise?
Not with a fixed plan that keeps increasing. Gentle activity within your limits is fine, and pacing to avoid crashes is the safest approach. A physiotherapist who knows ME/CFS can help.
Is ME/CFS the same as long COVID?
Not exactly, but many people with long COVID meet the criteria for ME/CFS, and the same pacing approach helps.
Helpful resources
- Emerge AustraliaAustralian ME/CFS support, information and advocacy. Free.
- NICE guideline NG206 (2021)The UK guideline on diagnosis and management. Free.
- CDC: ME/CFSUS information for patients and clinicians. Free.
Evidence and more information
- Institute of Medicine. Beyond myalgic encephalomyelitis/chronic fatigue syndrome: redefining an illness. 2015
- NICE. Myalgic encephalomyelitis (or encephalopathy)/chronic fatigue syndrome: diagnosis and management (NG206). 2021
- Snell CR et al. Discriminative validity of metabolic and workload measurements for identifying people with chronic fatigue syndrome. Phys Ther 2013
- van Campen CMC et al. Cerebral blood flow is reduced in ME/CFS during head-up tilt testing. Clin Neurophysiol Pract 2020
- Walitt B et al. Deep phenotyping of post-infectious ME/CFS. Nat Commun 2024
- Fluge Ø et al. B-lymphocyte depletion in ME/CFS: a randomized, double-blind, placebo-controlled trial. Ann Intern Med 2019
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