What are Fibroids?

One in five women between the ages of 18 and 50 will develop fibroids.  These are generally benign tumors of the womb, but they have been nicknamed "fireballs" by women having severe symptoms ranging from heavy bleeding to severe pain requiring a hysterectomy.  They are also responsible for 200,000 hysterectomies per year in the United States alone.  Also known as myomas or leiomyomas, fibroids are simply non-cancerous overgrowths of uterine smooth muscle cells.  These tumors are estrogen-dependent; they need estrogen in order to grow.  Fibroids increase throughout a woman's premenopausal years, affecting two out of every five women in their 40s.  Fibroids often grow most rapidly during the perimenopausal years, the 2-10 years preceding menopause when estrogen levels are high, but progesterone levels are low.  The good news is that fibroids generally shrink after menopause.  Their cause is unknown, although it is believed that some women may have a genetic predisposition.

Fibroids are generally located in the wall of the uterus, but can also grow inside the uterine cavity or on the outside of the uterus, either as an extension of the uterine wall or on a stalk ("pedunculated fibroids").  Rarely, fibroids can protrude or block the opening of the cervix, the mouth of the uterus.

Fibroids are extremely common, affecting one in four to one in five women.  The vast majority of women with fibroids, however, are unaffected and need no treatment.  They vary tremendously in size, from as small as a pea to as large as a pregnancy.  Women may have one fibroid or several.

Women who are symptomatic, are most likely to be over 35, and may experience a broad range of problems.  While there are now several non-surgical ways to manage fibroids, they are the most common reason for hysterectomy (removal of the uterus), which is the most common major operation performed on non-pregnant women in the U.S.

Created: 8/18/2003  -  Donnica Moore, M.D.