Excess estrogen and low levels of progesterone cause uterine lining thickening, or endometrial hyperplasia, explains Healthgrades. Estrogen causes uterine wall thickening in preparation for pregnancy, while progesterone helps to control the thickening and initiates the shedding of the lining of the uterus if pregnancy does not happen. Certain chronic diseases may also trigger the condition.
High levels of estrogen coupled with very low amounts of progesterone leads to excessive growth of cells on the uterine lining, according to Healthgrades. Endometrial hyperplasia can also occur as result of taking estrogen hormones without taking progesterone, which causes an imbalance of the two hormones. This can lead to cancer as well.
Risk factors for uterine line thickening include polycystic ovarian syndrome, a disorder that affects the levels of hormones in women; obesity; diabetes; and menopause, reports Healthgrades. Tracking menstrual periods, keeping diabetes under control and losing weight if overweight help to reduce the chances of endometrial hyperplasia. Taking birth control pills and, with the help of doctor, undertaking hormone replacement therapy may help as well.
Signs and symptoms include missed menstrual periods, acne, heavy bleeding during menstruation and bleeding between periods, notes Healthgrades. Other symptoms include hot flashes, tenderness of the vagina, dry vagina and mood swings. Rapid pulse, extreme abdominal pain, loss of consciousness and fainting require immediate medical attention.