What Are Uterine Fibroids?

Anatomy of Uterine Fibroids

Looking for Someone To Help?
Speak with a live educator
Educators are dedicated to answering your questions about uterine fibroids and the treatment options available to you.

If you are a woman between 30 and 50, there’s a good possibility that you or someone close to you is suffering from uterine fibroids. At least 25 percent of women in the United States have symptoms of uterine fibroids. In fact, about 70 percent of Caucasian women and more than 80 percent of African-American women have developed fibroids by the time they’re 50 years old. Many fibroids go undetected unless they cause symptoms. What are Uterine Fibroids?
The first concern of most women is: “Are fibroids cancer? Do they turn into cancer?” The answer to both questions is: “No.” Uterine fibroids (medically known as uterine leiomyomata) are common, non-cancerous (benign) tumors of the uterus consisting of smooth muscle cells and connective tissue. A woman may have one fibroid or groups of several fibroids. Fibroids range in size from less than 1 inch to more than 8 inches across. Where are fibroids located in the uterus? Along with size and shape, the location of uterine fibroids affects symptom severity and treatment decisions:

  • Submucosal fibroids – The uterus is lined with a “mucosal” layer of cells, somewhat like the moist lining of the stomach or the vagina. Some fibroids grow just beneath this mucosal lining
  • Intramural fibroids – The uterine walls are very muscular, so they can stretch during pregnancy and have the power to contract forcefully during childbirth. Some fibroids grow between muscle fibers, within the thick uterine wall
  • Subserosal fibroids – The outside of the uterus is covered with a “skin” of serous, non-secretory cells. Some fibroids grow just under this outer surface of the uterus
  • Pedunculated fibroids – Some submucosal and subserosal fibroids are attached to the uterus by stalks.