Evaluation of ME/CFS requires multiple stages based on patient symptoms and complete history, physical exam findings, review of any recent laboratory test results, and clinical judgment. As for any condition, healthcare providers typically determine the sequence and prioritization of laboratory testing based on individual patients’ presentations. While not all of the tests listed below may be needed initially or at the same time, the tests below are performed routinely for patient evaluations by healthcare providers with clinical expertise in ME/CFS, largely with the goal of identifying other illnesses:

  • Complete blood count with differential
  • Erythrocyte sedimentation rate (ESR)
  • Electrolytes
  • Fasting glucose
  • Renal function: creatinine, blood urea nitrogen (BUN), glomerular filtration rate
  • Calcium
  • Phosphate
  • Liver function: bilirubin, alanine aminotransferase (ALT), alkaline phosphatase (ALP), aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT), total protein, albumin/globulin ratio
  • C-reactive protein
  • Thyroid Function: thyroid-stimulating hormone (TSH), free thyroxine (free T4)
  • Iron studies to assess for both iron overload and deficiency: serum iron, transferrin saturation, ferritin
  • Celiac disease screening laboratory tests
  • Urinalysis

Despite being substantially debilitated, most people with ME/CFS have routine laboratory test results that are within normal ranges. Further testing may be indicated to confirm a diagnosis for illness other than ME/CFS if suggested by an individual patient’s history and/or physical findings. For example, if autoimmune disease is suspected, the healthcare provider may order additional tests such as antinuclear antibodies. However, healthcare providers should be cautious of extensive testing in the absence of clinical suspicion because of the risk of false-positive tests.

If abnormal laboratory findings are present, further evaluation is warranted. For example, if anemia is identified, further studies are generally indicated to characterize and treat the anemia. These studies might include tests for deficiencies in B12 and folate. Anemia can also be a presenting symptom of celiac disease. (Note: Some healthcare providers with expertise in the diagnosis and management of ME/CFS include vitamin level studies, including B12, folate, and vitamin D, in their initial testing. For patients with cognitive impairment, assessment of B12 and folate can help identify underlying conditions.)

Additional tests such as imaging and physiological assessments may be needed to diagnose underlying illnesses. These tests might include:

  • Specific cultures or serological tests if an ongoing or recent infection is suspected.
  • MRI or other neuroimaging procedures to evaluate abnormal findings on the neurological examination and to assess for diseases such as multiple sclerosis.
  • Physiological testing such as sleep studies, exercise testing (including VO2max), or tilt table testing to address specific questions, often in consultation with a specialist.

Be aware that a patient can have ME/CFS and a co-existing condition that causes fatigue or other ME/CFS symptoms (e.g., blood pressure abnormalities), and these co-existing conditions should be treated appropriately.

Extensive testing and frequent healthcare provider visits may exacerbate the symptoms of patients with ME/CFS, so when follow-up visits are needed, they need to be scheduled thoughtfully. Some patients with ME/CFS may not look ill during office visits, while those with more severe symptoms might not always be able to keep all of their appointments.

Assessing the Impact of Illness on Cognition

Tests can be useful to assess if and how patients’ cognitive skills, such as concentration, memory, and organization, are or become impacted by illness. This additional testing can also be useful in identifying particular areas in which specific tools or strategies might help. Assessments and strategic interventions may be particularly helpful to children and adolescents with ME/CFS. Academic attendance and performance are important for these patients, and their specific educational needs should be addressed.

Disclaimer: The content of this ME/CFS website is for informational purposes only and does not represent a federal guideline or recommendation for the treatment of ME/CFS. The information provided on this website is not intended to be a substitute for the medical judgment of the healthcare provider and does not indicate an exclusive course of action or treatment.