Exactly what causes chronic fatigue syndrome (CFS) is unknown, but there are several theories.
Some experts think a viral infection such as glandular fever can trigger the condition. Certain bacteria have also been suggested as a cause of CFS in some people, including types of bacteria responsible for pneumonia.
However, while tiredness is normal after a viral infection, this doesn’t explain why symptoms persist and get worse in CFS. Also, many cases of CFS don’t start after an infection, and this theory doesn’t explain why the condition sometimes develops gradually.
Other suggested causes of CFS include:
- problems with the immune system
- a hormone imbalance
- psychiatric problems – some cases have been linked to mental exhaustion, stress, depression and emotional trauma
- genes – some people may have an inherited tendency to develop CFS as it’s more common in some families
- traumatic events – some cases have been linked to events such as surgery or a serious accident
It’s possible CFS is caused by a combination of factors. Further research is necessary to confirm what causes the condition.
Debate over classification
The World Health Organization (WHO) has classified CFS as a chronic (long-term) neurological condition and this classification has been accepted by the Department of Health. However, the WHO’s decision remains controversial and isn’t accepted by everyone working in the field.
Members of the team of health professionals who drew up the National Institute of Health and Care Excellence (NICE) guidelines for CFS couldn’t agree that this classification is the right decision, and 84% of members of the Association of British Neurologists surveyed in 2011 said they didn’t view CFS as a neurological condition.
Source: NHS UK