N85.1: Endometrial adenomatous hyperplasia

The mucosal lining of your uterus is thicker than normal.

The wall of the womb is mainly made up of muscles. On the outside, a thin skin surrounds the uterus. On the inside, the uterus is lined with mucous membrane. This lining of the uterus thickens at the start of each normal menstrual cycle. It is then expelled when you have your period. This process is controlled by various sex hormones.

If there is an imbalance in sex hormone levels, the mucosal lining of the uterus may thicken permanently.

In most cases the mucous membrane is enlarged because the levels of the hormone estrogen in the body are too high. This can happen, for example, at the menopausal transition. Excess levels of estrogen may also be caused by being overweight, taking medication containing estrogen or by certain specific disorders of the ovaries.

If the mucosal lining of the uterus is permanently enlarged, women often have irregular or heavy periods. Post-menopausal women may find that they start to bleed from the vagina again.

If the mucosal lining thickens over a long period of time, the cells in the mucosal lining may mutate and grow rapidly. This may develop into endometrial cancer (cancer of the lining of the uterus).