Most cases of FM are mild or moderate, but one in four cases are severe or very severe. The severity of FM can roughly be divided into four levels:

Mild Cases

You can care for yourself and can do light domestic tasks, but with difficulty. You are still likely to be able to do a job, but may often take days off of work. In order to remain in work you are likely to have stopped most leisure and social activities. Weekends or other days off from work are used to rest in order to cope.

Moderate Cases

You have reduced mobility and are restricted in most activities of daily living. The level of ability and severity of symptoms often varies from time to time ("peaks and valleys"). You are likely to have stopped working and require rest periods, often sleeping in the afternoon for one or two hours. Night-time sleep tends to be poor and disturbed.

Severe Cases

You are able to carry out only minimal daily tasks such as face washing and cleaning teeth. You are likely to have severe difficulties with some mental processes such as concentrating. You may be wheelchair dependent for mobility and may be unable to leave your home except on rare occasions, and usually have severe prolonged after-effects from effort.

Very Severe Cases

You will be unable to carry out any daily tasks for yourself and are in bed for the majority of the time. You are often unable to tolerate any noise, and are generally very sensitive to light.