There are no medical tests for ME/CFS, which means that diagnosis can take a long time.

Doctors first need to take a careful medical history from you and your family, and find out how the condition is affecting your life. Blood tests are then usually taken to rule out other conditions that have similar symptoms to ME/CFS (which usually come back as normal).

Once other possibilities have been ruled out, a diagnosis of ME/CFS should be considered based on the characteristic pattern of the patient's symptoms and by matching them with an internationally agreed set of criteria such as the one defined by the CDC (Centers for Disease Control and Prevention). There are other criteria definitions prepared by other research teams, but this is the most recent and most widely recognised.

Because the definition says you need to have experienced fatigue for six months, the UK's Chief Medical Offiver says that "a diagnosis can and should be made well before this time, especially in children and young adults". So this might mean giving you a provisional diagnosis, then confirming it at six months if you still have the same symptoms. Anything that means a child or young person has been off school or work for three weeks or more should be taken seriously.

Our medical advisers at AYME believe that the most important part of diagnosis is for doctors and other health professionals to be aware of ME/CFS, and to actively listen to and understand a young person's medical history.

NICE definition of ME/CFS

ME Alliance Early Diagnosis Report
Executive Summary of the ME Alliance Early Diagnosis Report

CDC Case Definition Of Chronic Fatigue Syndrome
(International CFS Study Group 1994)

Conditions to be ruled out

  • Addison's disease
  • Anaemia
  • Chronic infections (such as Lyme disease or TB)
  • Chronic somatisation disorder
  • Coeliac disease
  • Immunodeficiency
  • Malignancy
  • Mood disorders (including anxiety and depression)
  • Multiple sclerosis
  • Myasthenia gravis
  • Sleep disorders
  • Rheumatic disease
  • Thyroid disease