what causes fibroids in the uterus

Uterine fibroids, also known as leiomyomas, are noncancerous growths in the uterus that affect up to 80% of women by age 50, often linked to a mix of genetic, hormonal, and lifestyle factors.

Main Causes

The exact cause isn't fully known, but research points to several key drivers. Hormones like estrogen and progesterone play a central role, as fibroids have more receptors for these hormones than normal uterine cells, promoting growth during reproductive years and shrinkage after menopause. Genetic changes in uterine muscle cells also contribute, with mutations like those in MED12 or HMGA2 genes found in many fibroids.

Other influences include growth factors (e.g., insulin-like growth factor) that support tissue maintenance, and extracellular matrix (ECM) buildup, which makes fibroids fibrous and stores growth-promoting substances.

Key Risk Factors

Certain factors raise the likelihood of developing fibroids, often interacting with causes above.

Factor| Description| Impact Level 15
---|---|---
Race/Ethnicity| African American women face highest risk, developing them younger with larger sizes.| High 12
Family History| Genetic predisposition if mother or sister had fibroids.| Moderate-High 15
Age & Hormones| Peak in 30s-40s; early periods or late menopause mean longer estrogen exposure.| Moderate 13
Obesity| Excess fat produces more estrogen.| Moderate 15
Diet| High red/processed meat, low greens/fruit/dairy; low Vitamin D.| Moderate 15
Alcohol| Increases risk, especially beer.| Low-Moderate 5

Recent Insights (2025)

A March 2025 UCLA Health article highlights how 80% of women develop fibroids, emphasizing Vitamin D deficiency and diets low in veggies as modifiable risks—echoing trends in ongoing research. No major breakthroughs on a single cause, but hormonal links remain strongest, with studies exploring gene therapies.

Prevention Tips

While not fully preventable, lifestyle tweaks may lower risk:

• Maintain healthy weight to balance hormones.
• Eat Vitamin D-rich foods (fish, fortified dairy) and plenty of greens.
• Limit red meat and alcohol.

"Fibroids tend to grow during pregnancy (high estrogen) and regress post- menopause."

TL;DR : No single cause—hormones, genes, and lifestyle converge; Black women and those with family history are at highest risk.

Information gathered from public forums or data available on the internet and portrayed here.