This might be of interest I believe? Sorry for bad grammar. If I was healthy I would have put in the necessary effort to write after a more academic standard. In my country we hade a diagnosis called "exhaustion syndrome" (ICD-10 code F43.8a). The symptoms are very similar to ME, but one criteria is that there has to have been stressors in the picture for the past 6 months. This is the diagnosis I have so far. But my research shows that there is no mutual international understanding of this diseases. In Norway they actually say it is the same thing as ME. BUT many patients with exhaustion syndrome do recover, but it sometimes takes years and rarely 100%. In US it is sometimes mistaken as a burnout, but in Swedish studies they are not seen as the same diagnosis. We also have chronic fatigue syndrome as an official diagnosis. I'm chocked of how confusing this is, and I can see that even the researchers and medical staff are confused. The exhaustion syndrome is a quite new diagnosis (somewhere in the 1990 when so many people got sick). Very few studies has been done, but the diagnose is highly common in Sweden (everyone knows someone who's gotten sick. It is so common we have a saying for it "went in to the wall".). In one article published in the doctors magazine (a newspaper for medical staff) they speculate that ME and Exhaustion syndrome are the same and also bring up this confusion. Here is the article: http://www.lakartidningen.se/Functions/OldArticleView.aspx?articleId=12353 Criteria for exhaustion syndrome: "Physical and mental symptoms of fatigue for at least two weeks. The symptoms have been developed because of one or more stressors that you have been exposed to for at least six months. The most prominent is a clear lack of mental energy. This can be seen in reduced entrepreneurship, reduced stamina or prolonged recovery time associated with mental strain (people with the diagnosis often feel misunderstood because of this criteria when they bring up the physical strain which are highly common). At least four of the following symptoms have occurred almost every day for two weeks: Memory Disorders Concentrations problems Clearly reduced ability to handle demands or to do things during time pressure Emotional lability or irritability Insomnia Clear bodily weakness or fatigue Physical symptoms such as aches, palpitation, chest pain, stomach ache, irritable bowel, dizziness, and sensitivity to sounds, light and scents. Your symptoms cause a clinically significant disorder or impaired function in work, social or other important aspects. The symptoms do not depend on any substance (such as drug addiction, medication) or any somatic disease / injury (such as hypothyroidism, diabetes, infectious disease)." Source: https://www.1177.se/Vasterbotten/Fakta-och-rad/Sjukdomar/Utmattningssyndrom/ According to Swedish specialists on the syndrome one common symptoms is also sensitivity to infections and new or worsened allergies due to immune system being weakened by long term cortisol damage. Source: https://www.stressmottagningen.nu. Common complaints can be "I feel like I'm about to get sick but I never become sick" or "I have this general feeling of being sick or feverish". But this is just the official criteria. When speaking to other people with the diagnose you quickly understand that the symptoms are highly individual and much more complex. Most patients will get bedridden for the first weeks/months. After that it is not unusual depending on severity that crashes come with mental or physical strain.