Diagnosis

There are no clinical tests for ME, which means that diagnosis can be a rather drawn-out affair.  Doctors first need to take a careful medical history from the young person and their family, to include details about how the illness is impacting on their lives.  Blood tests are then usually taken to rule out other conditions that have similar symptoms to ME.  These usually come back negative - normal.  Once this is done, a diagnosis of ME 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 below:

CDC case definition of chronic fatigue syndrome (International CFS Study Group 1994)

A thorough medical history, physical examination, mental status examination and laboratory tests must be conducted before a diagnosis can be made.  For a diagnosis to be made, 'A' must be present, then any four of 'B' must also be present.

A: Fatigue
Clinically evaluated, unexplained persistent or relapsing chronic fatigue that is of new or definite onset (ie. not lifelong), is not the result of ongoing exertion, is not substantially alleviated by rest, and results in substantial reduction in previous levels of occupational, educational, social or personal activities.

B Symptoms
Four or more of the following are needed in addition to fatigue.  These symptoms must have persisted or recurred during six or more consecutive months of illness and must not have predated the fatigue.

1) Substantial impairment in short term memory or concentration
2) Sore throat
3) Tender lymph nodes
4) Muscle pain
5) Multi-joint pain without joint swelling or redness
6) Headaches of a new type, pattern or severity
7) Unrefreshing sleep
8) Post-exertional malaise (feeling very unwell after exercise or activity) lasting more than 24 hours

NB.  There are other criteria definitions prepared by other research teams, but this is the most recent.

Several consultations may be necessary before a diagnosis can be made, but it is important that this does not delay diagnosis.  Often patients fail to get a diagnosis until their fatigue has been present for six months, which is consistent with current research criteria (see B above).  However, the CMO's report states that "a diagnosis can and should be made well before this time, especially in children and young adults"� even if a provisional diagnosis is given initially and confirmed at six months if symptoms persist (Annex 6 page 6-7).  Doctors should take seriously any illness that has kept a child away from school for more than three weeks (

Our medical advisors consider that the most important aspect of the diagnostic process is for doctors and other health professionals to be aware of ME and to actively listen to and understand the young person's unfolding clinical history. 

Article last edited on Thursday 13th August 2009                          Printable Version