Could You Have MECFS? from US Centers for Disease Control No characteristic laboratory abnormalities are approved to diagnose<unk> ; while physical abnormalities can be found, no single finding is considered sufficient for diagnosis. Blood, urine, and other tests are used to rule out other conditions that could be responsible for the symptoms. The CDC states that a medical history should be taken and a mental and physical examination should be done to aid diagnosis. Diagnostic tools The CDC recommends considering the questionnaires and tools described in the 2015 Institute of Medicine report, which include: * The Chalder Fatigue Scale * Multidimensional Fatigue Inventory * Fisk Fatigue Impact Scale * The Krupp Fatigue Severity Scale * DePaul Symptom Questionnaire * CDC Symptom Inventory for<unk>  * Work and Social Adjustment Scale (WSAS) * SF-36 / RAND-36 A two-day cardiopulmonary exercise test (CPET) is not necessary for diagnosis, although lower readings on the second day may be helpful in supporting a claim for social security disability. A two-day CPET cannot be used to rule out<unk> . Definitions Notable definitions include: * Centers for Disease Control and Prevention (CDC) definition (1994), the most widely used clinical and research description of<unk> , is also called the Fukuda definition and is a revision of the Holmes or CDC 1988 scoring system. The 1994 criteria require the presence of four or more symptoms beyond fatigue, while the 1988 criteria require six to eight. * The ME/CFS 2003 Canadian Clinical working definition states: "A patient with ME/CFS will meet the criteria for fatigue, post-exertional malaise and/or fatigue, sleep dysfunction, and pain; have two or more neurological/cognitive manifestations and one or more symptoms from two of the categories of autonomic, neuroendocrine, and immune manifestations; and the illness persists for at least 6 months". * The Myalgic Encephalomyelitis International Consensus Criteria (ICC) published in 2011 is based on the Canadian working definition and has an accompanying primer for clinicians The ICC does not have a six months waiting time for diagnosis. The ICC requires post-exertional neuroimmune exhaustion (PENE) which has similarities with post-exertional malaise, plus at least three neurological symptoms, at least one immune or gastrointestinal or genitourinary symptom, and at least one energy metabolism or ion transportation symptom. Unrefreshing sleep or sleep dysfunction, headaches or other pain, and problems with thinking or memory, and sensory or movement symptoms are all required under the neurological symptoms criterion. According to the ICC, patients with post-exertional neuroimmune exhaustion but only partially meet the criteria should be given the diagnosis of atypical myalgic encephalomyelitis. * The 2015 definition by the National Academy of Medicine (then referred to as the "Institute of Medicine") is not a definition of exclusion (differential diagnosis is still required). "Diagnosis requires that the patient have the following three symptoms: 1) A substantial reduction or impairment in the ability to engage in pre-illness levels of occupational, educational, social, or personal activities, that persists for more than 6 months and is accompanied by fatigue, which is often profound, is of new or definite onset (not lifelong), is not the result of ongoing excessive exertion, and is not substantially alleviated by rest, and 2) post-exertional malaise* 3) Unrefreshing sleep*; At least one of the two following manifestations is also required: 1) Cognitive impairment* 2) Orthostatic intolerance" and notes that "*Frequency and severity of symptoms should be assessed. The diagnosis of ME/CFS should be questioned if patients do not have these symptoms at least half the time with moderate, substantial, or severe intensity." Clinical practice guidelines are generally based on case descriptions, with the aim of improving diagnosis, management and treatment. An example is the ME/CFS guideline for the National Health Services in England and Wales, updated in 2021. Other guidance can be found at the New York Department of Health. Differential diagnosis Certain medical conditions can cause<unk>  fatigue and must be ruled out before a diagnosis of<unk>  can be given. Hypothyroidism, anemia, coeliac disease (that can occur without gastrointestinal symptoms), diabetes and certain psychiatric disorders are a few of the diseases that must be ruled out if the patient presents with appropriate symptoms. Other diseases, listed by the Centers for Disease Control and Prevention, include infectious diseases (such as Epstein–Barr virus, influenza, HIV infection, tuberculosis, Lyme disease), neuroendocrine diseases (such as thyroiditis, 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 bipolar disorder, schizophrenia, delusional disorders, dementia, anorexia/bulimia nervosa), neuropsychologic diseases (such as obstructive sleep apnea, parkinsonism, multiple sclerosis), and others (such as nasal obstruction from allergies, sinusitis, anatomic obstruction, autoimmune diseases, some<unk>  illness, alcohol or other substance abuse, pharmacologic side effects, heavy metal exposure and toxicity, marked body weight fluctuation). Ehlers–Danlos syndromes (EDS) may also have similar symptoms. Persons with fibromyalgia (FM, or fibromyalgia syndrome, FMS), like those with<unk> , have muscle pain, severe fatigue and sleep disturbances. The presence of allodynia (abnormal pain responses to mild stimulation) and of extensive tender points in specific locations differentiates FM from<unk> , although the two diseases often co-occur. Depressive symptoms, if seen in<unk> , may be differentially diagnosed from primary depression by the absence of anhedonia, decreased motivation, and guilt; and the presence of somatic symptoms such as sore throat, swollen lymph nodes, and exercise intolerance with post exertional exacerbation of symptoms.
Chronic fatigue syndrome
Hypothyroidism
Cancer-related fatigue
Idiopathic chronic fatigue
Da Costa's syndrome  Da Costa's syndrome  1
Exercise addiction
Medication phobia
Generalized anxiety disorder