Uterine fibroids are benign tumors in the uterus (womb). Their shape is usually round.

Uterine fibroids are classified according to their location in the uterus. There are:

  • subserosal fibroids, located beneath the serosa, which is a lining membrane on the outside of the uterus
  • submucosal fibroids, located inside the uterine cavity beneath the lining of the uterus, and
  • intramural fibroids, located in the uterine muscular wall.

There can be more than one fibroid. Uterine fibroids develop until the age of 50’s. After menopause, uterine fibroids most commonly shrink.



Some women may not have symptoms. If they do, the most common symptoms are:

  • Heavy menstrual bleeding in submucosal fibroids
  • Prolonged menstrual periods — seven days or more of menstrual bleeding
  • Pelvic pain
  • Frequent urination in subserosal fibroids, pressing the bladder
  • Constipation due to pressure on the rectum
  • Backache or leg pains
  • Acute pain when the fibroids begin to die



The exact cause of uterine fibroids is not known. The following issues are considered a possible cause:

  • genetic abnormalities
  • alterations in growth factor (proteins formed in the body that direct the rate and extent of cell proliferation) expression
  • abnormalities in the vascular system
  • estrogen level


Risk Factors

There are few known risk factors for uterine fibroids, other than being a woman of reproductive age. Other factors that can have an impact on fibroid development include:

  • Family history
  • Race. Black women have fibroids at younger ages
  • First menstruation at an early age
  • Eating red meat, less green vegetables and fruit, drinking alcohol, including beer



Uterine fibroids do not pose life-threatening situations, but may cause discomfort and the possible complication is anemia from heavy bleeding.

Another complication can be infertility or pregnancy loss due to submucosal fibroids. In this case, removal of fibroids is recommended.

In rare cases, fibroids can change the shape or block the fallopian tubes, by which the passage of sperm from the cervix to the fallopian tubes is obstructed.



Prevention of uterine fibroids is not possible because most of the causes are not controllable.