CFS can be hard to diagnose. It may take some time. This can feel frustrating. But, you can work to help ease your symptoms while you're waiting

The doctor will ask about your symptoms. You will also be asked about your family and health past. There are no standard tests for CFS. But, tests may be done to rule out other issues. People with CFS often have normal physical exams and test results.

If your tests are normal, the doctor may start to think you have CFS. The Institute of Medicine uses certain lists to diagnose CFS.

You must have all of these:

  • 6 months or more of lesser ability to keep an activity level that you had before the onset of illness. Fatigue doesn't get better with good sleep.
  • Severe fatigue or muscle fatigue at least 50% of the time with moderate to severe intensity.
  • Sleep problems at least 50% of the time with moderate to severe intensity.

Also, you must have one or both of these:

  • Problems with short-term memory or concentration, forgetfulness, or confusion at least 50% of the time. With moderate to severe intensity.
  • Lightheadedness or vision problems when standing or sitting up. Symptoms worsen when upright, but get better when lying down.

The tests you have are based on your health past, physical exam, and symptoms. Not everyone will have all tests. You may have:

Blood and Urine Tests

Blood tests may be done to check:

  • How your liver and kidneys are working
  • Calcium levels
  • Vitamin D levels
  • Red and white blood cell, and platelet counts—complete blood count (CBC)
  • Electrolyte levels such as salt and potassium
  • Inflammation—erythrocyte sedimentation rate (ESR)
  • Glucose levels
  • Phosphorus levels
  • Thyroid function—thyroid stimulating hormone (TSH)
  • Total protein levels
  • Iron levels

Urine tests can help to find infections or changes in the kidneys.

Psychological and Neurological Tests

The doctor may want to test mental skills. You may have tests for concentration, memory, and organization. A personality test can help to find out about your coping abilities. It's also done to look for any mental health problems such as:

Additional Tests

You may have:


Chronic fatigue syndrome. EBSCO DynaMed Plus website. Available at: Updated September 10, 2018. Accessed February 8, 2019.

Chronic fatigue syndrome. Merck Manual Professional Version website. Available at: Updated July 2018. Accessed February 8, 2019.

Committee on the Diagnostic Criteria for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome, Board on the Health of Select Populations, Institute of Medicine. Beyond myalgic encephalomyelitis/chronic fatigue syndrome: redefining an illness. Beyond Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Redefining an Illness. Washington (DC): National Academies Press (US); 2015 Feb 10. Available at:

Diagnosis of ME/CFS. Centers for Disease Control and Prevention website. Available at: Updated July 12, 2018. Accessed February 8, 2019.

Last reviewed December 2018 by EBSCO Medical Review Board Marcin Chwistek, MD  Last Updated: 2/8/2019