Uterine fibroids are tumors made of connective tissue and smooth muscle.
They grow slowly within the wall of the uterus or attach to the uterine wall. The uterus is the muscular organ at the top of the vagina. Babies develop in the uterus, and menstrual blood comes from the uterus. A uterine fibroid may be as small as a pea or as large as a grapefruit. As the fibroid grows, the uterus may become deformed or pushed aside.