The exact cause of uterine fibroids is not known, but researchers have identified several factors that may play a role. These factors include:

• Hormones: Two hormones called estrogen and progesterone cause the tissue that lines the inside of the uterus to thicken during each menstrual cycle to prepare for pregnancy. Fibroids appear to be affected by these hormones, and they tend to grow when hormone levels are higher, such as during pregnancy, and shrink when hormone levels are low, such as during the transition to menopause.

• Genetics: Many fibroids contain changes in genes that differ from those in typical uterine muscle cells. Researchers believe that uterine fibroids may develop from a stem cell in the smooth muscular tissue of the uterus. A single cell divides over and over, and in time, it turns into a firm, rubbery mass distinct from nearby tissue.

• ECM: ECM (extracellular matrix) is increased in fibroids and makes them fibrous. ECM also stores growth factors and causes biologic changes in the cells themselves.

• Race: Black people are more likely to have fibroids than people of other racial groups, and they have fibroids at younger ages than white people.

• Other factors: Other factors that may increase the risk of developing fibroids include starting menstruation at an early age, drinking alcohol, not eating enough fruit, exposure to diethylstilbestrol (DES), maternal pre-pregnancy diabetes or gestational diabetes, and being overweight or obese.

Its important to note that many women with fibroids do not have any symptoms, and not all fibroids require treatment. However, for those who do experience symptoms, treatment options include medications, surgery, or a minimally invasive treatment option known as uterine fibroid embolization.