Diagnosis of chronic fatigue syndrome (CFS), also known as chronic fatigue and immune
dysfunction syndrome (CFIDS), is a time-consuming and difficult process which is generally arrived at by excluding other illnesses with similar symptoms and comparing a patient's symptoms with the 1994 International case definition. As yet, there is no indicator or diagnostic test that can clearly identify the disorder. Overlapping symptoms can occur with several conditions, such as fibromyalgia, Gulf War Illnesses and multiple chemical sensitivities. Many diseases have similiar symptoms including lupus, hypothyroidism and Lyme disease and these need to be considered when making a diagnosis.
What You Can Expect
Your physician will take a medical history, asking questions about your past health (you will probably be asked to
complete a written form - often done before your appointment time). It is likely that you will be asked
about your past and current mental health as well. You can expect to receive a basic physical exam. Several
types of routine blood tests and those that exclude alternative diagnoses are almost certain to be
ordered. Other tests that are designed to identify central nervous system problems or viral syndromes
may be ordered as well, depending on your symptoms. It's important to answer questions honestly and completely
- and don't hesitate to ask your own questions. If you have thought of questions before your appointment, it's
a good idea to write these down and bring them with you. Also, bring a list of medications and
supplements that you're taking - be sure to include dosages. In addition, bring paper and pen with you
to write down instructions. If cognitive problems interfere with the ability to write instructions or understand
them, ask a friend or family member to accompany you.
Diagnostic Criteria / Case Definition
In 1994 an updated case definition was developed by an international working group of CFS experts. Although the criteria were designed to be used for research purposes, physicians utilize them as diagnostic guidelines for CFS. The case definition criteria calls for four of eight symptoms to be present along with fatigue that interferes with physical, mental, social and educational activities. Both the fatigue and symptoms must have occurred for [at least] a six month period. People with CFS may experience many more than the eight symptoms named in the case definition,
so knowledgeable physicians will take this fact into consideration when making a diagnosis (after other
possible reasons for symptoms have been ruled out).
Waiting for the Diagnosis
After testing has been completed and the physician has ruled out alternative diagnoses, he or she will inform you of the probable diagnosis. If you have research articles and other CFS factual information, you may wish to share this with your doctor while in the diagnostic process. With CFS, it's not uncommon for patients to be better informed than
many physicians, so feel free to courteously share your knowledge. The diagnostic process may be lengthy some people wait many months (or years) to be diagnosed. It may take an enormous amount of patience. In the meantime, talk with your doctor to work out the best treatment plan for symptom reliefand to improve function.
We're Here for You
If you are typical of the person with CFS, obtaining a diagnosis has been a frustrating experience. You are not alone in your frustration. Support and understanding are offered at the CFIDS Association Web site. You're invited to
continue your search through the Association's Web site to discover more about treatment, research, support and resources.
To complement the wealth of information available on the Associationís websites, we offer free, downloadable Fact Sheets on a variety of topics to help people better understand the complex nature of CFS, engage in more meaningful conversations with their health care providers and make informed choices about CFS-related decisions. Easily reproducible, these Fact Sheets are ideal for distribution to health care professionals, family members and the general public.