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, which stands for myalgic encephalomyelitis. Many people refer to the condition as CFS/ME.
CFS/ME can affect anyone, including children. It's more common in women, and tends to develop between your mid-20s and mid-40s.
New guidelines on CFS/ME are currently being developed by NICE. The draft guidelines suggest structured exercise programmes, such as graded exercise therapy (GET) will no longer be recommended to treat CFS/ME.
Once the full guidelines are published we'll update this page to reflect any changes.
The main symptom of CFS/ME is feeling extremely tired and generally unwell.
In addition, people with CFS/ME may have other symptoms, including:
Most people find overexercising 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, so it's important to see a GP to get a correct diagnosis.
There is not a specific test for CFS/ME, so it's diagnosed based on your symptoms and by ruling out other conditions that could be causing your symptoms.
The GP will ask about your symptoms and medical history. You may also have blood and urine tests.
As 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 do not get better as quickly as expected.
Treatment for CFS/ME aims to relieve the symptoms. Your treatment will depend on how CFS/ME is affecting you.
Most people with CFS will improve over time, especially with treatment, although some people do not 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.
It's not known what causes CFS/ME, but 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:
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.
ME Association is a charity that provides information, support and practical advice for people affected by the condition.
You can find a local support group on their website.