There are insufficient studies as to the better treatment for severely ill or disabled sufferers, the evidence base for children and young people is scarce and for the remaining sufferers the level of documentation is low or very low. The diagnostic criteria used in different studies varies, which makes comparisons difficult. Empirical studies about treatment experiences are missing. CFS/ME is a disease with subjective symptoms without objective findings and the qualitative studies show that patients feel stigmatized and mistrusted and that the doctors find diagnosing and treating CFS/ME challenging. In addition to these aspects the prevalence, prognosis and cause of CFS/ME remains unclear. There seems to be next to unlimited research needed.