What is Chronic Fatigue Syndrome (CFS)?
A person with CFS feels completely worn-out and overtired. This extreme tiredness makes it hard to do the daily tasks that most of us do without thinking — like dressing, bathing, or eating. Sleep or rest does not make the tiredness go away. It can be made worse by moving, exercising, or even thinking. CFS can happen over time or come on suddenly. People who get CFS over time get more and more tired over weeks or months. People who get CFS suddenly feel fine one day and then feel extremely tired the next. A person with CFS may have muscle pain, trouble focusing, or insomnia (not being able to sleep). The extreme tiredness may come and go. In some cases the extreme tiredness never goes away. The extreme tiredness must go on for at least 6 months before a diagnosis of CFS can be made.