Although low back pain is a symptom, not a disorder, estimates of its prevalence are included in the report because of its pervasiveness. The authors estimate that about one-half of adults have low back pain in any given year. Approximately 15 percent of U.S. adults report frequent back pain or pain lasting more than 2 weeks annually. Overall, more than 26 million Americans ages 20 to 64 and almost 6 million ages 65 and older have frequent low back pain. Fibromyalgia prevalence rates were estimated at 3.7 million Americans ages 18 and older.
Prevalence is much lower in men than in women.
A chronic condition, fibromyalgia is characterized by widespread pain, greater sensitivity to pain, sleep disturbances, fatigue, and multiple tender points. The authors note that the fibromyalgia data are extrapolated from a study that may not reflect the prevalence of the United States as a whole. We recognize the importance of fibromyalgia and wanted to be able to provide some estimate. Rheumatoid arthritis occurs more frequently in women than in men. They note that these figures may be an overestimate.