Mental symptoms such as concentration difficulties, memory problems and not being able to find the right words are also commonly described by people with fatigue. Problems with sleep and mood are common. It is when fatigue is more severe then expected, or when it goes on for a long time that sufferers may seek help. Help may also be needed if the fatigue affects ability to work or to carry out normal everyday tasks. Usually the problem will have developed gradually over a period of time.
Individuals often carry on trying to cope for some time, but eventually find it too difficult.
The cause of CFS is unknown. Usually there is more than one reason why fatigue problems develop. For example, completely denying the condition and over-exerting oneself, or in contrast, reacting with fear and severely limiting one's activities, can both be unhelpful. Anti-depressants can help with fatigue and muscle pain. This can lead to a misunderstanding of one's body.