Fibroids are common, benign (non-cancerous) tumours of smooth muscle usually occurring in the uterus (womb). Fibroids can vary from the size of a pea to bigger than a grapefruit. They can grow in various positions on the uterus. The symptoms a woman has will depend on the number, size and position of the fibroids. Fibroids do not produce symptoms in all women, but may lead to prolonged or heavy menstrual bleeding, pressure or pain in the pelvis, and rarely to infertility. In addition to hysterectomy (surgical removal of the uterus), less invasive surgical procedures are used to remove uterine fibroids. In more than 99 percent of fibroid cases, the tumors are benign (non-cancerous).