The ICD has variations in each country. In the US, it's called ICD-CM. In the current version, ICD-9-CM, ME is not classified in the tabular listing of diseases, meaning it doesn’t “exist”. I’ve heard of only a handful of ME patients in the US able to get diagnosed with ME. Everyone else has been diagnosed with CFS.
Luckily for us, this has been rectified in the ICD-10-CM, which goes into effect Oct. 1 2015. G93.3 (the code for ME), will then be listed in the tabular listing of diseases making it officially "exist". The timing could not be better. We need to start using it!
It also has an Exclude1 for CFS (R53.82). The same with CFS – it has an Exclude1 for ME. This means you can't be diagnosed with both ME and CFS at the same time. ME G93.3 is listed under neurological diseases. CFS R53.82 is listed under Symptoms, Signs and abnormal clinical and laboratory findings, not elsewhere classified. So – the ICD-10-CM officially states that ME and CFS two separate diseases, classified in two different categories, each mutually exclusive of each other.
The language we use is important, and using the correct language to refer to our disease will help reinforce our campaign. MEadvocacy.org, along with our sponsor May12.org, and the National Campaign for ME have already started using the term ME to mean true ME. We will no longer be using the term CFS, or even worse, the mixed name ME/CFS*, to mean ME. When we mean ME, we will say ME.