There's no test for chronic fatigue syndrome (CFS), but there are clear guidelines to help doctors diagnose the condition.
A GP should ask you about your medical history and give you a physical examination.
It can take a while for CFS/ME to be diagnosed because other conditions with similar symptoms need to be ruled out first.
In the meantime, you may be given some advice about managing your symptoms.
Guidelines from the National Institute for Health and Care Excellence (NICE) say doctors should consider diagnosing CFS/ME if a patient has extreme tiredness that cannot be explained by other causes and the tiredness:
- started recently, has lasted a long time, or keeps coming back
- means you cannot do the things you used to do
- gets worse after activity or gentle exercise, such as a short walk
You must also have some of these symptoms:
- problems sleeping, such as insomnia
- muscle or joint pain
- a sore throat or sore glands that are not swollen
- problems thinking, remembering or concentrating
- flu-like symptoms
- feeling dizzy or sick
- fast or irregular heartbeats (heart palpitations)
- doing exercise or concentrating makes your symptoms worse
The GP should consult a specialist if they're unsure about the diagnosis or if you have severe symptoms.
If a child or young person under 18 has symptoms of possible CFS/ME, they should be referred to a paediatrician within 6 weeks of first seeing a doctor about their symptoms.
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.
The diagnosis should be confirmed by a doctor after other conditions have been ruled out, and if your symptoms have lasted at least:
- 4 months in an adult
- 3 months in a child or young person
For more detailed information, see the NICE guidelines on how CFS/ME is diagnosed.