Fibroids, which are noncancerous growths that develop inside and around the uterus. They can increase bleeding in a few ways. For example, they can put pressure on the walls of the uterus, making it harder for it to contract and control bleeding. Read more
Endometriosis is a long-term condition in which endometrial tissue that is meant to grow along the uterine lining goes rogue and ends up growing in places outside the uterus (for example, on your ovaries). This tissue sheds every month, along with your period, causing a heavier flow. It can also become inflamed, which leads to pain and bleeding. Read more
Adenomyosis is similar to endometriosis, with one main difference: instead of endometrial tissue growing outside the uterus, in adenomyosis, it grows into the muscles of the uterus.
Dysfunctional uterine bleeding is a common condition that causes vaginal bleeding to occur outside of your period.
Cervical abnormalities can cause excess bleeding. For example, cervical erosion is when cells that normally line the inside of your cervix start growing on the outside of your cervix (the lower end of the uterus). These cells are more sensitive and can cause bleeding or spotting during or after sex. They can also lead to vaginal discharge that contains blood.
Blood thinning medications that are used to treat blood clots can increase the time it takes for blood clots to form. This, in turn, leads to more bleeding.
Gynaecological cancers, while rare, can lead to changes in your normal periods including heavier periods and bleeding between periods.