How Common Are Fibroids?
While the exact percentage of the prevalence of uterine fibroids is unknown (women living with fibroids) prevalence), fibroids are an undeniably common condition. One of the reasons why it is difficult to estimate the prevalence of uterine fibroids is that many women living with fibroids are asymptomatic. Estimates of true prevalence range anywhere from 5% to 21% of all women.¹
As dedicated fibroid specialists, we like our patients to have access to the most reliable medical evidence on the topic, so we'll review a few of the highest-quality studies to help you better understand the epidemiology of uterine fibroids.
Prevalence of Symptomatic Uterine Fibroids
One high-quality cross-sectional survey-based study of almost 22,000 reproductive-age women (age 15 to 49) across 8 countries (USA, UK, Brazil, Canada, France, Germany, Italy, South Korea) found the prevalence of uterine fibroids ranging from 4.5% (UK) to 9.8% (Italy) of women. The prevalence in the US was 6.9%.¹ One of the shortcomings of this research was that asymptomatic women were not included in the study. In other words, the entire 6.9% of US women who reported fibroids were symptomatic - hence the relatively lower prevalence estimates compared to other studies that have counted symptomatic and asymptomatic cases.
Prevalence of Asymptomatic Uterine Fibroids
Another high-quality study randomly selected US women ages 35-49 and screened them for uterine fibroids. The study found that 60% of African-American women had developed uterine fibroids by age 35.
By age 50, that figure increased to 80%. Likewise, 40% of caucasian women had developed fibroids by age 35, and almost 70% by age 50.² The majority of these women did not report fibroid symptoms. This study has also helped to establish that uterine fibroids are significantly more common in African-American women than in women of other racial profiles.
While the majority of fibroid cases are asymptomatic and therefore go undetected, fibroids are still extremely common even when we only consider symptomatic cases.
 Zimmermann, A., Bernuit, D., Gerlinger, C., Schaefers, M., & Geppert, K. (2012). Prevalence, symptoms and management of uterine fibroids: An international internet-based survey of 21,746 women. BMC Women’s Health, 12(1), 6.
 Day Baird, D., Dunson, D. B., Hill, M. C., Cousins, D., & Schectman, J. M. (2003). High cumulative incidence of uterine leiomyoma in black and white women: Ultrasound evidence. American Journal of Obstetrics & Gynecology, 188(1), 100–107.