However, a chronic illness such as chronic fatigue syndrome provides less than obvious clues that someone is actually sick. To provide a better understanding, the definition, as described by Chronic Fatigue Syndrome: The Nurse's Role (2003), is characterized by extended periods of extreme, debilitating fatigue and related symptoms. These related symptoms include fatigue that is not due to ongoing exertion, and is not alleviated by rest, as well as a reduction in occupational, education, social or personal activities. Some minor symptoms, as per Lewis, Heitkemper & Dirksen (2000), include: substantial loss of short-term memory, or concentration; sore throat; tender cervical or axillary lymph nodes; muscle pain; multijoint pain without joint swelling or tenderness; and headaches of new type, pattern or severity. .
Many health care providers do not trust that this illness actually exists, however, it does, although the percentage of those affected is less than 1% in the United States (Lewis, Heitkemper & Dirksen), affecting three times more women than men. Chronic fatigue syndrome (CFS), also known as chronic mononucleosis, chronic Epstein-Barr (EBV) infection, and glandular fever, usually occurs between the ages of 25 to 45, and in some studies, it was found that the onset was brought on after a viral infection or acute stress. An over-the-phone survey conducted in Wichita, Kansas, concluded that 235 per 100 000 persons suffered from CFS, 373 of that total being women, and the remaining 83 were men (Reyes, Nisenbaum, Hoaglin, Unger, 2003, p 1530). Also included in this journal were prevalancies from countries around the world. A physician-based survey reported that out of four cities over the course of four years, there were less than 1 per 100 000 incidences of persons affected. In Japan, it was estimated that 0.46 per 100 000 persons were diagnosed with CFS annually. Furthermore, a study in England conducted on patients with prospective glandular fever would possibly be diagnosed with a "fatiguing illness that would otherwise be classified as CFS" (Reyes, Nisenbaum, Hoaglin, Unger, 2003, p 1530).