The exact cause of
uterine fibroids is not known. Fibroids begin when
cells overgrow in the muscular wall of the uterus.
After a fibroid
develops, the hormones
progesterone appear to influence its growth. A woman's
body produces the highest levels of these hormones during her childbearing
menopause, when hormone levels decline, fibroids
usually shrink or disappear.
Uterine fibroids (leiomyomata) are noncancerous growths that develop in or just outside a woman’s uterus (womb). Uterine fibroids develop from normal uterus muscle cells that start growing abnormally. As the cells grow, they form a benign tumor.