Chronic fatigue syndrome (CFS)

Chronic fatigue syndrome (CFS) is a long-term illness with a wide range of symptoms. The most common symptom is extreme tiredness. CFS is also known as ME (myalgic encephalomyelitis). The condition can affect anyone, including children. It's more common in women. It tends to develop between your mid-20s and mid-40s.

Symptoms of CFS/(ME)

There's some debate over the correct term to use for the condition. The information on this page will refer to the condition as CFS/ME.

The main symptom of CFS/ME is feeling extremely tired and generally unwell.  This usually occurs after physical activity. The symptoms may be delayed for a day or more and may take several days to end.

In addition, people with CFS/ME may have other symptoms, including:

Most people find over exercising makes their symptoms worse. 

The severity of symptoms can vary from day to day, or even within a day. 

The symptoms of CFS/ME are similar to the symptoms of some other illnesses.  It's important to see your GP to get a correct diagnosis.

Diagnosing CFS/ME

There isn't a specific test for CFS/ME. It's diagnosed based on your symptoms and by ruling out other conditions that could be causing your symptoms. 

Your GP will ask about your symptoms and medical history. You may also have blood and urine tests.

The symptoms of CFS/ME are similar to those of many common illnesses that usually get better on their own. A diagnosis of CFS/ME may be considered if you don't get better as quickly as expected.

Treating CFS/ME

Treatment for CFS/ME aims to relieve the symptoms. Your treatment will depend on how CFS/ME is affecting you.

Treatments include:

  • cognitive behavioural therapy (CBT) 
  • a structured exercise programme or management of activity and rest periods,  depending upon individual symptoms/response
  • medication to control symptoms (not cure)

Most people with CFS improve over time, although many people with CFS don't make a full recovery. It's also likely there will be periods when your symptoms get better or worse. Children and young people with CFS/ME are more likely to recover fully.

Causes of CFS/ME

It's not known what causes CFS/ME. There are a number of theories, for example, it may be triggered by an infection, or certain factors could make you more likely to develop the illness. 

Suggested causes or triggers for CFS/ME include:

  • viral infections, such as glandular fever
  • bacterial infections, such as pneumonia
  • problems with the immune system
  • a hormone imbalance 
  • mental health problems, such as stress, depression and emotional trauma
  • your genes – CFS/ME seems to be more common in some families

Living with CFS/ME

Living with CFS/ME can be difficult. Extreme tiredness and other physical symptoms can make it hard to carry out everyday activities. You may have to make some major lifestyle changes.

CFS/ME can also affect your mental and emotional health, and have a negative effect on your self-esteem.

As well as asking your family and friends for support, you may find it useful to talk to other people with CFS/ME, see useful links below.

The information on this page has been adapted from original content from the NHS website.

For further information see terms and conditions.

This page was published February 2018

This page is due for review September 2020

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