Intramural fibroids are one of three types of uterine fibroids that can be found growing in or on the uterus . They can cause painful symptoms and heavy bleeding and can also affect fertility. Discover which size of fibroid is dangerous is crucial for health and treatment options. This guide covers everything from symptoms to treatment for fibroids . Intramural fibroids grow within the wall of the uterus. Submucosal fibroids grow into the space inside the uterus. Subserosal fibroids grow on the outside of the uterus. Some submucosal or subserosal fibroids hang from a stalk inside or outside of the uterus. This is called a pedunculated fibroid. Intramural uterine fibroids are the most common type of fibroid, also called intramural leiomyomas, and they can affect fertility, menstrual health, and pregnancy outcomes.