Fibroids are very common. They m a y occur in 2 or 3 out of every 10 women over age 35. They occur most often in women between ages 30 and 50, although women in their 20s sometimes have them. It is common to have more than one fibroid. Fibroids can grow in response to stimulation by the
hormone estrogen, produced naturally in the body. These growths can show up as early as age 20 and shrink after menopause when the body stops producing large amounts of estrogen.
Fibroids may grow in different parts of the uterus. They are named according to which part of the uterus they are found Fibroids that grow inside the wall of the uterus are called intramural fibroids. They are the most common type of fibroid.