Uterine fibroids (fibroid tumors, leiomyomas, or myomas) are noncancerous (benign) muscular tumors that grow in the wall of the uterus (womb). Symptoms can include long and heavy periods, cramping, a feeling of fullness or pressure on the abdomen (belly), low back pain, pain with sexual intercourse (dyspareunia), and the frequent urge to urinate.