Fibroids are growth of muscle and fibrous tissue that can develop in and around your womb. Fibroids can be divided into three main types, based on the location where they have grown.
Intramural fibroids develop inside the wall of your uterus. The uterine wall is made up of muscle. These fibroids grow within the muscle, so they don’t stick out into your womb or out into your body, which can make them trickier to remove if you need surgery. However, they are often smaller and less likely to cause symptoms because they are contained within the uterus wall.
Subserosal fibroids stick out from the outside of the uterine wall, into the surrounding pelvic area. The fibroid may be largely embedded within the wall or it may stick out on a narrow stalk. Subserosal fibroids can grow very large because there is a lot of space around them.
Submucosal fibroids also stick out from the uterine wall, but they are on its inner side. They protrude into the womb itself. Like the subserosal fibroids, they can be partly embedded in the wall or attacked to it by a stalk. Submucosal fibroids are more likely to cause heavy bleeding and other menstrual problems, because they are growing into the womb lining.
As well as appearing in different places, fibroids can also vary in terms of their size and the effect that they are having on your health. The smallest fibroids might only grow to the size of a pea, but in some cases, fibroids that are left untreated can grow much bigger. The largest fibroids can actually reach the size of a melon. If you have a vary large fibroid or lots of smaller ones, you may start to develop symptoms such as heavy periods and pelvic pain. Your fertility can also be affected. You may need to take medication to reduce your symptoms or shrink the fibroids. In some cases, surgical removal of the fibroids may be needed.