| According to the 1994 Fukuda definition[2] there | | | | frequently run a low fever, or report fever-like |
| are eight main categories of symptoms in CFS: | | | | symptoms (sweating, feeling too hot or cold, etc.) |
| Fatigue: People with CFS experience profound, | | | | without measurable fever temperature. |
| overwhelming exhaustion, both mental and | | | | Sleep problems: "Unrefreshing sleep" and rest is a |
| physical, which is worsened by exertion, and is not | | | | hallmark of CFS, and insomnia is also common. |
| relieved (or not completely relieved) by rest. To | | | | Maintaining a sleep schedule is extremely difficult |
| receive a diagnosis of CFS, this fatigue state | | | | for many patients. Vivid, "feverish" dreams are a |
| must last for six months. | | | | symptom in many people with CFS, exacerbating |
| Pain: Pain in CFS may include muscle pain, joint pain | | | | disturbed sleep patterns. Patients report that |
| (without joint swelling or redness, and may be | | | | exercise, unlike in healthy persons, worsens the |
| transitory), headaches (particularly of a new type, | | | | insomnia and unrefreshing sleep symptoms alike. |
| severity, or duration), lymph node pain, sore | | | | Psychological/Psychiatric symptoms: emotional |
| throats, and abdominal pain (often as a symptom | | | | lability, anxiety, depression, irritability, and |
| of irritable bowel syndrome). Patients also report; | | | | sometimes a curious emotional "flattening" (most |
| bone, eye and testicular pain, neuralgia and painful | | | | likely due to exhaustion), may manifest in CFS |
| skin sensitivity. Chest pain has been attributed | | | | patients. Many of these symptoms can be directly |
| variously to microvascular disease or | | | | caused by the CFS mechanism or, in some cases, |
| cardiomyopathy by researchers, and many | | | | may be secondary symptoms created by the |
| patients also report painful tachycardia. | | | | syndrome, as many chronic pain or illness patients |
| Cognitive problems: people with CFS may | | | | also show similar psychiatric issues. CFS patients |
| experience forgetfulness, confusion, difficulty | | | | with pre-existing psychiatric symptoms may |
| thinking, concentration difficulties, and "mental | | | | report that these worsen with the onset of CFS. |
| fatigue" or "brain fog". Additional signs may be | | | | Treatment for psychiatric symptoms alone does |
| experienced; in the 2003 Canadian Definition these | | | | not relieve the physical symptoms of CFS, |
| include aphasia, agnosia, and loss of cognitive body | | | | indicating that the disease is not psychological in |
| map[7][8]. | | | | nature. |
| Hypersensitivity: people with CFS are often | | | | Disturbances in the autonomic nervous system |
| sensitive to light, sound, and multiple chemicals and | | | | and hormones: |
| foods. Many CFS patients report an increase in | | | | People with CFS often have abnormalities in the |
| allergic-type sensitivity to foods, scents, and | | | | autonomic nervous system such as low blood |
| chemicals, and many also report a sensitivity to | | | | volume, orthostatic intolerance, dizziness and |
| medications, which can complicate treatment. | | | | light-headedness, especially when standing up |
| Patients with pre-existing allergies, asthma, and | | | | quickly. |
| similar conditions often report a worsening of | | | | Hormonal abnormalities may include abnormal |
| symptoms. Sensory overload is commonly | | | | vasopressin metabolism and a blunted ACTH |
| reported by patients, leading to increased fatigue | | | | response, leading to hypothyroidism and/or low |
| and even migraine or seizures. | | | | cortisol and reduced ability to respond to |
| Poor temperature control: people with CFS often | | | | physiological and emotional stress. Patients |
| report either feeling too hot or too cold, possibly | | | | sometimes show abnormally low levels of |
| due to involvement of the hypothalamus, which | | | | testosterone, growth hormone and other |
| regulates body temperature. Many CFS patients | | | | important hormones. |