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Diagnosing CFS
On this page:
- Diagnostic Challenges
- Clinical Evaluation
- Illustration of how patients are evaluated for CFS
- Diagnostic Criteria
- Exclusionary Conditions
Diagnosing chronic fatigue syndrome (CFS) can be complicated by a number of factors: 1) there's no diagnostic laboratory test or biomarker for CFS, 2) fatigue and other symptoms of CFS are common to many illnesses, 3) CFS is an invisible illness and many patients don't look sick, 4) the illness has a pattern of remission and relapse, 5) symptoms vary from person to person in type, number and severity, and 6) no two CFS patients have exactly the same symptom set.
These factors have contributed to an alarmingly low diagnosis rate. Of the four million Americans who have CFS, less than 20% have been diagnosed.
Because there is no blood test, brain scan or other lab test to diagnose CFS, it's a diagnosis of exclusion. Your health care professional will first take a detailed patient history, including a review of medications that could be causing your fatigue. A thorough physical and mental status examination will also be performed. Next, a battery of laboratory screening tests will be ordered to help identify or rule out other possible causes of your symptoms. Your professional may also order additional tests to follow up on results of the initial screening tests.
Explanation of how patients are evaluated for CFS
Your clinician should consider a diagnosis of CFS if these two criteria are met:
- Unexplained, persistent fatigue that's not due to ongoing exertion, isn't substantially relieved by rest, is of new onset (not lifelong) and results in a significant rEducation in previous levels of activity.
- Four or more of the following symptoms are present for six months or more:
- Impaired memory or concentration
- Postexertional malaise (extreme, prolonged exhaustion and sickness following physical or mental activity)
- Unrefreshing sleep
- Muscle pain
- Multijoint pain without swelling or redness
- Headaches of a new type or severity
- Sore throat that's frequent or recurring
- Tender cervical or axillary lymph nodes
Chronic fatigue syndrome can resemble many other illnesses, including mononucleosis, Lyme disease, lupus, multiple sclerosis, fibromyalgia, primary sleep disorders, severe obesity and major depressive disorders. Medications can also cause side effects that mimic the symptoms of CFS.
Because CFS can resemble many other disorders, it's important not to self-diagnose CFS. It's not uncommon for people to mistakenly assume they have chronic fatigue syndrome when they have another illness that needs to be treated. If you have CFS symptoms, consult a health care professional to determine if any other conditions are responsible for your symptoms. A CFS diagnosis can be made only after other conditions have been excluded.
It's also important not to delay seeking a diagnosis and medical care. CDC research suggests that early diagnosis and treatment of CFS can increase the likelihood of improvement.
Page last modified on May 3, 2006
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