No one knows for certain what causes M.E. - not even doctors and scientists.
What we do know so far is this:
Some people are more likely to develop M.E. than others. It maybe something to do with the genes we have and our family background. It affects girls more often than boys but that doesn't mean it's a 'girly' illness.
Scientists have spotted 'triggers' that might start the illness. Most often triggers can be a virus or an infection, like the flu or glandular fever. Very rarely it may be triggered by a vaccination or poisons in the environment. Some people have reported that they think an accident or operation helped to start the illness or even stress, together with another trigger such as an infection.
Lack of sleep, being depressed or having a lot of worry, doing too much, or even not enough, can all slow down your recovery.
The problem is that more research is needed to find out exactly why people get M.E. It is still something of a mystery.
Information produced July 2003
Updated June 2004
