Myalgic Encephalopathy / Chronic Fatigue Syndrome/ (ME/CFS)

Chronic fatigue syndrome (ME/CFS) is a complex condition that causes long-term, fluctuating, and energy-draining fatigue, which does not improve with rest or sleep.

Alternative names for chronic fatigue syndrome

Myalgic encephalomyelitis; myalgic encephalopathy (ME); Chronic fatigue syndrome; post-viral fatigue syndrome; PVFS; systemic exertional intolerance disease SEID.

What is ME/CFS?

ME/CFS is a very poorly understood condition and a source of considerable distress to sufferers and their loved ones. It is characterised by a severe worsening of symptoms after physical or cognitive exertion. People with ME/CFS have a range of symptoms that can affect every system of the body. Physical examination and investigations do not help diagnose ME/CFS but exclude other conditions with similar symptoms. These include infections and many endocrine disorders, for example, diabetes mellitus and abnormalities of the thyroid, cortisol or calcium metabolism.

What causes ME/CFS?

The cause of ME/CFS is not known. It is thought that about 70% of cases of ME/CFS may follow a viral infection such as glandular fever.

ME/CFS can occur at any age, but it commonly affects people in their 20s to 40s. There is a female to male ratio of approximately 4:1. Finally, chronic stress and major life events may contribute to ME/CFS development.

Other factors that could make you more likely to develop ME/CFS include bacterial infections, weakened immune system, hormone imbalances, mental illnesses (e.g. physical or emotional trauma) and genetic factors.

What are the signs and symptoms of ME/CFS?

The symptoms vary depending on the severity of the condition. The major symptom is disabling fatigue which is worse after physical or mental exertion and not relieved by rest. ME/CFS is usually diagnosed after symptoms have been present for at least six months in adults, and other causes for the symptoms have been excluded. The symptom severity is very variable, with approximately 25% of people suffering from severe debilitating symptoms, which may leave them housebound or even bed-bound. This fatigue can often vary over time, with good and bad days. Over-exertion, either physical or mental, frequently makes symptoms of ME/CFS worse. In addition to fatigue, many other symptoms can occur in people with ME/CFS.

Other common symptoms include:

  • poor memory and concentration (‘brain fog’)
  • muscle pain (myalgia)
  • pains in key parts of the body and head (trigger points)
  • sore throat and a feeling of swollen glands in the neck
  • palpitations, lowered blood pressure and fainting
  • irritable bowel with diarrhoea and constipation
  • inner ear infection (labyrinthitis) with dizziness and vertigo
  • sensitivity to noise and light.

Muscle and joint pain can be very severe and be overlap with fibromyalgia. The difference between this and ME/CFS usually depends on the main symptom – pain or fatigue, respectively.

How common is ME/CFS?

It is estimated that around 250,000 people have chronic fatigue syndrome in the UK. It is most common in women in their mid-20s and mid-40s.

Is ME/CFS inherited? 

ME/CFS does appear to run in families. Some studies suggest various genes that may be inherited and increase your risk of developing ME/CFS. However, environment and lifestyle factors also appear to play a role.

How is ME/CFS? 

There is no one diagnostic test to confirm ME/CFS. The diagnosis is currently based on clinical symptoms and the exclusion of other conditions with similar symptoms. If you have had symptoms for around three to six months, you should be assessed by a doctor. A full clinical examination must be carried out to exclude other conditions. If red flag features are identified, your doctor may need to undertake further tests.

A panel of blood tests is recommended in all patients suspected of having ME/CFS. Depending on your particular symptoms, you may need additional tests to rule out other conditions, including hormone problems.

ME/CFS challenges our current healthcare culture because we have not yet found a widely agreed way to diagnose and treat the condition. It remains poorly understood even though it can cause immense suffering and loss of wellbeing and can, in some cases, be very debilitating or even life-threatening.

The lack of a diagnostic test leads some healthcare professionals to make an incorrect diagnosis, such as putting symptoms down to depression or stress. When faced with doctors indicating they can find no abnormality, people suffering severely from ME/CFS can feel very frustrated. This is why educating doctors about ME/CFS and validating symptoms is important.

How is ME/CFS treated?

There is no universal treatment for ME/CFS. Treatments will vary depending on individual circumstances. Even with treatment supported by an experienced ME/CFS team, recovery is frequently slow and can take months or more. Setbacks can affect the speed of progress.
Pacing your physical and mental activity is central to aiding recovery. Establishing a structured day and weekly schedule with regular sleep and wake times is helpful. Pacing should be dovetailed with lifestyle approaches, including a healthy diet (plant-based whole foods), drinking adequate amounts of fluid, improving sleep hygiene, avoidance of high-intensity exercise and, where possible, managing chronic stress. These approaches are likely to help with all long-term conditions.

Established treatments for ME/CFS are currently disputed and controversial, even though many high-quality studies have been undertaken.

One of the problems with current treatments is that they do not identify or treat the underlying cause. At the same time, they can help manage the condition.

The NICE clinical guidance on ME/CFS was first published in 2007. A revised version of the guidance was published in October 2021 which no longer recommends graded exercise therapy, with the mainstay of treatment centred around pacing and activity management delivered through teams of healthcare professionals specialising in managing ME/CFS. Also, medication to help with pain, sleep problems, or coexisting medical problems may be prescribed by your doctor in specific circumstances depending on individual need.

ME/CFS may coincide with or even result in depression, particularly if individuals are not diagnosed and provided with support.

ME/CFS itself is not helped by hormone treatment, but if you suffer from ME/CFS and have a thyroid problem, menopause or other hormone problem, optimising those conditions will be likely to help with your overall symptoms and wellbeing.

Any medication treatment used in people with ME/CFS should be monitored and supervised by a doctor carefully. Some of the medications may not be well tolerated and may also have side effects.

There are many unproven and often costly treatments offered within the private sector to people with ME/CFS. This is a factor of the lack of universally effective treatments for people ME/CFS. It is important to be cautious and speak to your doctor before considering a private treatment that may cause you harm or be very costly to you.

Are there any side-effects to the treatment?

The treatments currently available through the NHS include management from a team of healthcare professionals specialising in ME/CFS. As mentioned above, treatments include pacing, activity management, lifestyle approaches, GET and CBT. Treatment needs to be tailored to individual need. They should help symptoms in the longer term.

GET has become increasingly controversial. If activity is built up too quickly, it can cause a “boom and bust” scenario and make symptoms worse. This has led to some patients feeling that GET is dangerous. NICE is currently assessing the evidence carefully with new NICE guidance expected to be published in the near future. The aim is to improve the quality and success of treatment and reduce any risk of harm or symptoms worsening in the long term.

What are the longer-term implications of ME/CFS?

Response to treatment and recovery varies depending on the severity of the condition.
Overall, the longer-term outlook for most people with ME/CFS should be regarded as good. Earlier diagnosis and management from a specialist team appears to result in better outcomes.
The majority of people with mild to moderate symptoms will improve. Many will return to normal or relatively normal health with the right support and treatment.

Full recovery is less likely in people with very severe and long term symptoms or who suffers from multiple other health conditions (co-morbidities).

Patients with ME/CFS sometimes experience setbacks (relapses) in their condition when their symptoms can increase after a period of recovery. It is not always clear what the cause of a relapse is. In this situation, you should work with your doctor to find a suitable treatment regime that works for you.

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Last reviewed: Aug 2022