There are multiple definitions of CFS/CFIDS/ME. Which not only makes it confusing for patient and doctors, it can make diagnosis difficult, and even affect scientific research. I’m going to lay out the different definitions here, to serve as a guide for those who are looking for more clarity. I’ll start today by offering the definition used widely in the US, and in future posts, I’ll talk about the UK and Canada.
Note: I don’t support or agree with many of these definitions- they are hard to understand, difficult to use as a tool for diagnosis, some were written by the experts in the field while others were not, and some have not been updated for decades despite new research and evidence. I am merely providing you with the information your doctor may be working with, with the hope that you may be able to better communicate.
The CDC (Center for Disease Control and Prevention) in the US came up with this criteria in 1994. Most doctors/insurance companies use this definition when diagnosing a patient. These criteria are also known as the Fukada definition of CFS. You can find the full set of guidelines here: http://www.cfids-me.org/cdcdefine.html
The basics are as follows:
1. The patient must have fatigue that is long lasting (chronic), from an unknown cause (unexplained), and must not be life long (ie not since birth). This fatigue is not made better by resting, and has affected likely numerous parts of your life.
2. For six months or more, the patient must have at least HALF of the following symptoms:
Difficulty with memory or concentration
Tender lymph nodes
Joint pain (without swelling or redness)
Headaches (that are different from any kind you had before you had CFS)
Feeling tired even after sleeping
Fatigue from physical activity. The kind of fatigue that lasts more than 24 hours
3. The patient should be tested to make sure the symptoms are not caused by another condition. A few are listed specifically:
Iatrogenic conditions (like side effects of medications)
Illnesses that have been treated but came back such as Hepatitis B or C
Bipolar affective disorders
Alcohol or substance abuse
Severe Obesity (defined as a BMI greater than 45)
Routine and further tests should be done to rule out other diagnosis such as Multiple Sclerosis
4. There are some conditions that do NOT rule out the diagnosis of CFS (meaning you could have one of these AND CFS, or your previous diagnosis was wrong and you only have CFS):
Nonpsychotic or melancholic depression
Multiple Chemical Sensitivity Disorder
Treated Lyme Disease