In medicine, doctors refer to the layer of mucus membranes which lines the uterus as the endometrial cavity. The cells which make up this layer are called endometrial cells. In humans, the endometrial cavity renews itself monthly, as part of the reproductive cycle of healthy women. The body builds up a dense layer of tissue which could support a fetus, and if a woman is not impregnated, the endometrial cells are shed in the form of a menstrual period. An assortment of health problems are associated with the endometrial cavity, which is one of the reasons why it is important to get frequent medical check-ups.

One of the most common issues involving endometrial cells is endometriosis. Endometriosis is caused by the growth of endometrial cells outside of the uterus. Most commonly, these clusters of cells grow in the abdomen, but they can appear in other parts of the body. Just like the cells in the endometrial cavity, they respond to the hormone cycles of the body by shedding and attempting to detach. However, since they lack an escape route, the cells cause internal bleeding, scarring, and sometimes intense pain. The condition can be difficult to diagnose, and generally appears in women between 25 and 35 years of age, although it has been recorded in girls as young as 11.

Cancers of the endometrial cavity are also common among women. This type of cancer most commonly occurs in women who are past reproductive age, and because it is slow growing, it can be quickly arrested and stopped if a woman and her doctor are alert. Endometrial cancer causes abnormal vaginal bleeding, so women should keep track of their menstrual cycles, and report irregularities to a physician. If a doctor suspects cancer in the endometrial cavity, a biopsy will be performed to obtain tissue samples to test. Women should be aware that a PAP smear does not always reveal endometrial or uterine cancers, as it is taken from the area of the cervix.

Fluid can also build up in the endometrial cavity. Among women of reproductive age, this is usually associated with pregnancy. In older women, however, it may be a sign of a problem. If an ultrasound reveals a buildup of fluid in the endometrial cavity, a biopsy will be performed to determine whether or not the cause is benign. Fluid is not always a cause for alarm. Women should rely on the judgment of their doctors to determine whether or not the fluid in the endometrial cavity should be further investigated or not.