The World Health Organization classes chronic fatigue syndrome as a central nervous system disease.Some neuroimaging studies have observed prefrontal and brainstem hypometabolism; however, sample size was limited. Neuroimaging studies in persons with CFS have identified changes in brain structure and correlations with various symptoms. Results were not consistent across the neuroimaging brain structure studies, and more research is needed to resolve the discrepancies found between the disparate studies.Tentative evidence suggests a relationship between autonomic nervous system dysfunction and diseases such as CFS, fibromyalgia, irritable bowel syndrome, and interstitial cystitis. However, it is unknown if this relationship is causative. Reviews of CFS literature have found autonomic abnormalities such as decreased sleep efficiency, increased sleep latency, decreased slow wave sleep, and abnormal heart rate response to tilt table tests, suggesting a role of the autonomic nervous system in CFS. However, these results were limited by inconsistency.Central sensitization, or increased sensitivity to sensory stimuli such as pain have been observed in CFS. Sensitivity to pain increases after exertion, which is opposite to the normal pattern. Immunological
Immunological abnormalities are frequently observed in those with CFS. Decreased NK cell activity is found more often in people with CFS and this correlates with severity of symptoms. People with CFS have an abnormal response to exercise, including increased production of complement products, increased oxidative stress combined with decreased antioxidant response, and increased Interleukin 10, and TLR4, some of which correlates with symptom severity.
In many chronic illnesses, aerobic exercise is beneficial, but in chronic fatigue syndrome, the CDC does not recommend it. The CDC states:Any activity or exercise plan for people with ME/CFS needs to be carefully designed with input from each patient. While vigorous aerobic exercise can be beneficial for many chronic illnesses, patients with ME/CFS do not tolerate such exercise routines. Standard exercise recommendations for healthy people can be harmful for patients with ME/CFS. However, it is important that patients with ME/CFS undertake activities that they can tolerate...

Counseling
The CDC states that counseling may help patients cope with pain caused by CFS, and that talking with a professional counselor or therapist may help people to more effectively manage the symptoms that affect their quality of daily life. Nutrition
A proper diet is a significant contributor to the health of any individual. Medical consultation about diet and supplements is recommended for persons with CFS. Persons with CFS may benefit from a balanced diet and properly supervised administration of nutritional support if deficiencies are detected by medical testing. Risks of nutritional supplements include interactions with prescribed medications. Treatment
Cognitive behavioral therapy
NICE indicates CBT might be offered to help cope with the difficulty of dealing with the symptoms of ME/CFS, but should not be intended to be curative. The rationale behind the use of CBT to change beliefs about the illness is disputed.