Risk factors of uterine fibroids Uterine fibroids develop from a smooth muscle stem cell in the uterus, which divides repeatedly until a mass — aka a fibroid — is created, says Misal.

Uterine fibroids are tumors made of muscle that can grow on your uterus. They rarely turn into cancer. Many women have uterine fibroids. You might not even know you have them, since they don’t ...