The community prevalence of FM is reported as 1% in the United Kingdom and up to 5% of the total U.S. population (approximately 3.4% of all women and 0.5% of men). That is, 7 to 10 million Americans have FM. In the US, approximately 90% of those diagnosed are women between the ages of 20 and 50. It occurs in females to males in an approximate ratio of 20 to 1.
Although FM is not life threatening, and in most cases does not cause permanent damage, it can negatively affect quality of life.