Differential diagnosis

Differential diagnosis in ME/CFS is the process which tries to make a correct diagnosis by excluding other diseases which can cause similar symptoms, for example other fatiguing or painful illness.

ME/CFS
Many diseases can cause similar symptoms ME/CFS: However, if strict diagnostic criteria and diagnostic testing for other conditions is used, misdiagnosing a patient suffering from the conditions above with ME/CFS is unlikely.
 * infectious diseases (such as Epstein–Barr virus, influenza, HIV infection, tuberculosis, Lyme disease)
 * neuroendocrine diseases (such as Hashimoto's thyroiditis (hypothyroidism), Addison's disease, adrenal insufficiency, Cushing's disease)
 * hematologic diseases (such as occult malignancy, lymphoma)
 * rheumatologic diseases (such as fibromyalgia, polymyalgia rheumatica, Sjögren's syndrome, giant-cell arteritis, polymyositis, dermatomyositis)
 * psychiatric diseases (such as depression, bipolar disorder, schizophrenia, delusional disorders, dementia, anorexia/bulimia nervosa)
 * neuropsychologic diseases (such as obstructive sleep apnea, parkinsonism, multiple sclerosis)
 * others (such as nasal obstruction from allergies, sinusitis, anatomic obstruction, autoimmune diseases such as lupus or rheumatoid arthritis, some other chronic illness, alcohol or substance abuse, pharmacologic side effects, heavy metal exposure and toxicity, marked body weight fluctuation)

Multiple Sclerosis
Neurological symptoms, such as POTS symptoms and dysautonomia are very common in ME/CFS patients, those same symptoms are common in M.S. as well. Furthermore M.S. can often present with fatigue and post-exertional malaise.

Notable studies

 * 2021, Clinical Profile and Aspects of Differential Diagnosis in Patients with ME/CFS from Latvia - (Full text)
 * 2000, Differential diagnosis: The challenge of chronic fatigue - (Full text)