Chronic Fatigue Syndrome (CFS) Diagnosis
A diagnosis of chronic fatigue syndrome (CFS) is based on the following criteria:
- Severe, chronic fatigue that lasts for at least 6 months in 50% of time and is not due to another illness or medical cause
- At least four of the following eight symptoms:
- Impairment of short-term memory or concentration
- Sore throat
- Tender lymph nodes
- Muscle pain
- Joint pain without swelling or redness
- Sleep that is not refreshing
- Prolonged fatigue lasting 24 hours or more after exercise
If you have these symptoms, your doctor will conduct more tests. The tests will look for other causes of the symptoms. This may involve:
Your doctor will ask you for a detailed medical history. A complete physical exam will be done.
Standardized Lab Tests
You will receive a standard series of tests. This should help your doctor identify other possible causes of illness. If no cause is identified, your doctor may make a diagnosis of CFS.
The number and type of tests may vary depending on your history. The following tests are often used to exclude other causes of fatiguing illness:
- Alanine aminotransferase (ALT) (liver test)
- Albumin (liver test)
- Alkaline phosphatase (ALP) (bone and liver test)
- Blood urea nitrogen (BUN) (kidney test)
- Complete blood count (white and red cells)
- Creatinine (kidney test)
- Electrolytes (salt and potassium)
- Erythrocyte sedimentation rate (ESR) (inflammation test)
- Globulin (liver test)
- Glucose (blood sugar)
- Thyroid stimulating hormone (TSH)
- Total protein
- Transferrin saturation (iron level)
If one of the tests above suggest an illness, your doctor may order more tests. This is done to confirm an illness other than CFS. Additional tests may include:
- Lyme disease antibody
- Cytomegalovirus (CMV) titer
- Test for mononucleosis (heterophile test)
- Tests for candida
- Tests for viral hepatitis
- HIV test
Your doctor may want to assess the impact of CFS on certain mental skills. You may have tests for your concentration, memory, and organization. You may also be given a personality assessment. This can help to determine your coping abilities. It is also done to identify any coexisting affective disorders. This includes depression , panic disorder , or other anxiety disorders .
Centers for Disease Control and Prevention website. Available at:
Craig T, Kakumanu S. Chronic fatigue syndrome: evaluation and treatment.
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National Institute of Allergy and Infectious Diseases website. Available at:
Prins JB, van der Meer JW, Bleijenberg G. Chronic fatigue syndrome.