Fibroids are abnormal growths that develop in or on a woman’s uterus. Sometimes these tumors become quite large and cause severe abdominal pain and heavy periods. In other cases, they cause no signs or symptoms at all.
The growths are typically benign, or noncancerous. The cause of fibroids is unknown.
Fibroids are also known by the following names:
- leiomyomas
- myomas
- uterine myomas
- fibromas
According to the National Institutes of Health (NIH), about up to 80 percent of women have them by the age of 50. However, most women don’t have any symptoms and may never know they have fibroids.
The type of fibroid a woman develops depends on its location in or on the uterus.
Intramural fibroids
Intramural fibroids are the most common type of fibroid. These types appear within the muscular wall of the uterus. Intramural fibroids may grow larger and can stretch your womb.
Subserosal fibroids
Subserosal fibroids form on the outside of your uterus, which is called the serosa. They may grow large enough to make your womb appear bigger on one side.
Pedunculated fibroids
Subserosal tumors can develop a stem, a slender base that supports the tumor. When they do, they’re known as pedunculated fibroids.
Submucosal fibroids
These types of tumors develop in the middle muscle layer, or myometrium, of your uterus. Submucosal tumors aren’t as common as the other types.
It’s unclear why fibroids develop, but several factors may influence their formation.
Hormones
Estrogen and progesterone are the hormones produced by the ovaries. They cause the uterine lining to regenerate during each menstrual cycle and may stimulate the growth of fibroids.
Family history
Fibroids may run in the family. If your mother, sister, or grandmother has a history of this condition, you may develop it as well.
Pregnancy
Pregnancy increases the production of estrogen and progesterone in your body. Fibroids may develop and grow rapidly while you’re pregnant.
Women are at greater risk for developing fibroids if they have one or more of the following risk factors:
- pregnancy
- a family history of fibroids
- age of 30 or older
- African-American
- a high body weight
Your symptoms will depend on the number of tumors you have as well as their location and size. For instance, submucosal fibroids may cause heavy menstrual bleeding and trouble conceiving.
If your tumor is very small or you’re going through menopause, you may not have any symptoms. Fibroids may shrink during and after menopause. This is because women undergoing menopause are experiencing a drop in their levels of estrogen and progesterone, hormones that stimulate fibroid growth.
8 Symptoms of fibroids may include:
- heavy bleeding between or during your periods that includes blood clots
- pain in the pelvis or lower back
- increased menstrual cramping
- increased urination
- pain during intercourse
- menstruation that lasts longer than usual
- pressure or fullness in your lower abdomen
- swelling or enlargement of the abdomen
