Diagnosis

Personal and Medical History

A doctor should first take a careful personal and family medical history, which may include a psychological profile, as well as perform a thorough physical examination. Patients should be prepared to answer questions such as:

• When did the fatigue first begin?
• Does anything make it worse or better?
• Is it better at certain times of the day?
• Does physical activity make it worse?
• Are there any other symptoms?
• Has anyone else in the family ever complained of fatigue?
• Is your personal and professional life stressful?

The doctor may also ask about any changes in weight or request a patient to monitor morning and afternoon body temperatures. The patient should report any drugs being taken, including vitamins and over-the-counter or herbal medications.

Laboratory Tests

Inexpensive tests, including thyroid and liver function tests, blood count, and sedimentation rate, are typically recommended to rule out specific conditions that can cause persistent fatigue. No blood, urine, or other laboratory test can specifically diagnose CFS. If any test is abnormal, it is not useful for diagnosing CFS specifically, and the doctor should look for other causes of these abnormalities.

That being said, research published in 2005 found that certain components in urine were unique in people with CFS, and may someday be considered biomarkers of the disease. Additionally, antibodies to Epstein-Barr virus and increased levels of isoprostanes, markers of oxidative stress, have been found in the blood of people with CFS.

Exercise Tests

Some experts recommend exercise tests. In general, CFS patients cannot exercise to the capacity of their peers. A 2003 study found that exercise capacity varied widely among patients who met the AMA guidelines for chronic fatigue syndrome. Therefore, exercise tests may help determine the severity of the condition. Some studies suggest that CFS patients have higher-than-normal ratings of perceived exertion (RPE), which describes the effort attributed to exercise. In a 2003 study, however, the perceptions of how hard they were exercising did not differ between CFS patients and their non-CFS peers. Interestingly, a 2005 Dutch study found the volume of gray matter in the brain to be markedly reduced in people with CFS. Such brain shrinkage has been linked to lower rates of physical activity in people with CFS.

Tilt Test for Neurally Mediated Hypotension

Simply measuring blood pressure will not identify CFS patients in whom the syndrome might be caused by neurally mediated hypotension (an abnormal drop in blood pressure). A tilt test, whereby the person lies on a table tilted upright at a 70-degree angle for a prolonged period, may confirm CFS caused by neurally mediated hypotension if the patient feels lightheaded, sick, and faint after several minutes.

Ruling Out Chronic Fatigue Syndrome

Among the many other common conditions that can lead to feelings of temporary exhaustion are the following:

• Depression
• Infections
• Pregnancy
• Extreme exercise
• Excessive stress