The people who say they have it are usually 18-25 years old, or 40-50 years old.. but usually the younger age & female. the symptoms are fatigue, body aches that have no redness or swelling, feeling tired, sleeping a lot, brain fog, weakness, memory loss, exercise intolerance, and depression, and this lasts for years or even decades and it was in the news recently where a mother blamed her daughters death on cfs. CFS people are adamant their condition has a physical and non psychological cause and have given doctors death threats and compared them to Nazi doctors if they make any conclusions that CFS is not caused by something physical, like a new virus. CFS itself has many names, such as ME, Post Exertional Intolerance Syndrome, and 'Yuppie Flu'. The demographic is usually women in their 40's. Many odd things have been blamed, for instance 'chemtrails', stress, vaccinations, gut bacteria, or even a new virus that doctors are covering up (the virus one is the most common). there are few doctors who will diagnose and the criteria is that every single known disease must be ruled out. it seems to have made a sudden appearance in the 1980's, and it was prevalent in the 90's, but then it seemed to wane and now it's prevalent again and it's like every other person has it.