Chronic fatigue syndrome

Chronic fatigue syndrome is a condition that causes long-term and energy-draining tiredness, which does not improve with rest or sleep.

Alternative names for chronic fatigue syndrome

Myalgic encephalomyelitis; myalgic encephalopathy; CFS; ME; post-viral fatigue syndrome; PVFS

What is chronic fatigue syndrome?

Chronic fatigue syndrome is a very challenging condition and a source of considerable distress to both patients and doctors. Patients have a range of symptoms but nothing abnormal can be found on physical examination or investigation. 

Fatigue is a common symptom of many endocrine disorders, for example, diabetes mellitus or abnormalities of the thyroid, cortisol or calcium metabolism. However, the pattern with chronic fatigue syndrome is usually different and, with relatively simple investigations, it is usually fairly easy to exclude any underlying hormonal abnormality.

What causes chronic fatigue syndrome?

Doctors simply do not know what causes chronic fatigue syndrome. They know there are links, with many patients having had severe glandular fever (Epstein Barr virus), and there are some studies to show that the body’s immune response to glandular fever is greater in patients with chronic fatigue syndrome. Sometimes a viral infection can be shown as the trigger for chronic fatigue syndrome, but not always. Blood tests do not show any evidence of any ongoing active viral infection and treatment with anti-viral drugs has not proven to be effective. So the most likely cause of chronic fatigue syndrome is in the way an individual responds to, and recovers from, a virus they have had. 

What are the signs and symptoms of chronic fatigue syndrome?

Signs and symptoms have been clearly documented with national guidance based on a number of symptoms. These symptoms vary depending on the severity of the condition. The major symptom is disabling fatigue, whether mild, modest or severe, which has been present for at least four months in adults. Patients can usually distinguish this kind of fatigue from others, such as too much physical activity. This fatigue can often vary over time, with good and bad days. Over-exertion, either physical or mental, can often make it worse. In addition to fatigue, there is often a pattern of sleep disturbance such as difficulty getting to sleep, waking frequently and waking unrefreshed, even after a long sleep.  

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
  • labyrinthitis with dizziness and vertigo
  • sensitivity to noise and light.

Muscle and joint pain can be very severe and be diagnosed as fibromyalgia. The difference between this and chronic fatigue syndrome usually depends on the main symptom – pain or fatigue, respectively. 

How common is chronic fatigue syndrome?

It is estimated that in the UK, around 190,000 people have chronic fatigue syndrome. It is most common in people in their 40s and 50s. Women are diagnosed with chronic fatigue syndrome more frequently than men but this may be because men are less likely to see their doctor.

Is chronic fatigue syndrome inherited? 

Chronic fatigue syndrome does appear to run in families. There have been some studies suggesting various genes that may be inherited and increase the risk of developing chronic fatigue syndrome. However, it is generally considered that the tendency to occur in more than one family member is because of a shared environment or lifestyle.

How is chronic fatigue syndrome diagnosed? 

There is no specific test to diagnose chronic fatigue syndrome. Patients who have had symptoms for around three to four months should be seen by a doctor and have a full history and examination taken. It is important that a full clinical examination is carried out, which should be normal. Blood pressure is often low but there should not be a significant drop when going from sitting to standing (postural hypotension). Pulse rate may be quicker than normal (sinus tachycardia) but there should not be an abnormal heart rhythm and the doctor may need to undertake an echocardiogram (ECG). There should be no abnormalities in the neurological examination, although the reflexes are often quite brisk.

A number of blood tests are recommended in all patients and, depending on particular symptoms, additional tests may be needed. To exclude hormonal problems, thyroid function and calcium levels should be included in all blood tests. In men, it is advisable to check testosterone levels. Cortisol deficiency is rare but should be tested for. A cortisol level test at 9 a.m. may be sufficient, but it might also be necessary to undertake a more complex short synacthen test, where a hormone similar to pituitary adrenocorticotropic hormone is injected into the bloodstream to stimulate the adrenal glands. The cortisol level in the blood is measured immediately before the injection is given and again after 30–60 minutes. This can still be undertaken as an outpatient. 

In some ways, chronic fatigue syndrome challenges the whole philosophy of medicine and the way that our society views health. Traditionally, there has been a less than sympathetic response from the medical profession, resulting in inappropriate diagnoses such as depression or stress. When faced with doctors indicating they can find no abnormality, patients have often felt frustrated and they have criticised the doctors for not conducting the appropriate tests or finding the obvious diagnosis.  

How is chronic fatigue syndrome treated?

Unfortunately, there is no simple remedy for chronic fatigue syndrome. Treatments will vary depending on each case and, while a successful outcome is likely, it will take some time, usually months or more, and will usually require a change in lifestyle. 

Lifestyle is extremely important, including a healthy diet with three meals per day, drinking adequate amounts of fluid and improving sleep pattern. This may be helped by medication, but it is important for sufferers to try and get to bed at a reasonable time – ideally 10–11 p.m. – and wake at a reasonable time. The only two treatments proven to be helpful are exercise in gradual stages and cognitive behavioural therapy (CBT). However, these have only been proven to be effective when given as a part of a wider treatment programme delivered by a range of different professionals.   

Graded exercise is essentially limiting physical activity to a level that sufferers are comfortable with on their worst days, and only gradually increasing the amount of exercise while avoiding over-exertion. 

Cognitive behavioural therapy concentrates on helping people cope with the frustration of the condition and the limitations that it sets on their lifestyle and ambitions.

Steroid therapy or treatment with thyroxine in patients with normal thyroid function is not recommended. The typical symptoms of chronic fatigue are not those of depression. However, the two often coincide and chronic fatigue syndrome is a very depressing condition, so an approach that treats both is often helpful. Patients are often intolerant of medication, so, while low-dose amitriptyline (a type of antidepressant) can be particularly helpful to improve sleep pattern and pain, it may not be very well tolerated.

There are a lot of unproven treatments and, within the private sector, a lot of individuals and organisations that are making a great deal of money selling these treatments. These include vitamin B12 injections, immunoglobulin therapy, anti-viral therapy and multivitamins. 

Are there any side-effects to the treatment?

The recognised therapies of graded exercises and cognitive behavioural therapy have no side-effects, particularly if patients work with the teams that are trying to help them. 

As mentioned before, there are a lot of unproven treatments offered for chronic fatigue syndrome within the private sector. Care should be taken, as it is unlikely that these treatments have been properly tested using controlled clinical trials for any side-effects that they might cause.

What are the longer-term implications of chronic fatigue syndrome?

Overall, the longer-term outlook for patients with chronic fatigue syndrome should be regarded as good, particularly if sufferers are diagnosed fairly soon after the onset of their symptoms, and are treated appropriately. However, it must be recognised that there is no quick-fix for this condition and treatment may need to last for many months. Response does vary depending on the severity of the condition and a full recovery is less likely in somebody with very severe symptoms, but the majority of people with mild to moderate symptoms will improve and many will return to relatively normal health. This will, however, require significant lifestyle change, often reducing the levels of physical activity for a period of time, including reducing intense work patterns, which can have implications both financially and academically. 

Patients with chronic fatigue syndrome do sometimes experience setbacks (relapses) in their condition, when their symptoms increase after a period of time. It is not always clear what the cause of a relapse is. Individuals should work with their doctor to find a suitable treatment regime that works for them.

Last reviewed: Feb 2018