Estrogen is one of two sex hormones that a woman possesses. The other is progesterone. We normally associate testosterone with men, but women need it, too. Estrogen is beneficial to a woman in many ways, including enabling her to have a menstrual period, get pregnant and carry a child to term. It is also good for the skin, hair and virtually every organ in her body. However, estrogen can get too high, and when it does this is considered estrogen dominance. This term is the invention of the late Dr. John Lee, who did extensive research in progesterone and its relationship to estrogen.
When a woman’s body is functioning optimally, estrogen levels aren't too high or too low. Estrogen peaks as a woman prepares for her menstrual period. During this time, a woman may experience PMS or premenstrual symptom because of the increase in estrogen. Estrogen levels decline once ovulation occurs, at which time progesterone is produced and takes over. When a woman stops ovulating regularly, as she heads toward menopause, progesterone production is sporadic. Progesterone is not made if ovulation does not occur. As a consequence, there is nothing to keep estrogen levels in check, which is one of the services that progesterone provides. When progesterone isn’t present, estrogen levels can sky-rocket, resulting in estrogen overload.
When a woman is pregnant, her estrogen levels are supposed to be high. When she is not pregnant, high levels of estrogen can result in night sweats, mood swings, tender and sore breasts, sleep disruptions and hot flashes—the typical peri-menopausal symptoms. High levels of estrogen are a common occurrence during peri-menopause and this results in estrogen dominance or overload.
A woman’s estrogen levels can also be impacted by outside influences, reports WomenToWomen.com. Man-made chemicals that are defined as xenoestrogens are present in the environment. Xenoestrogens can disrupt our endocrine system. When estrogen levels get too high, because of xenoestrogens or naturally, this can cause breast cancer, infertility and auto-immune disorders.
High estrogen levels can also be caused by ovarian hyper-stimulation syndrome (OHSS), according to Clarian.org. This is sometimes the result of when a woman takes fertility drugs to stimulate egg production.
If a woman has a functioning adrenocortical tumor, this can produce too much estrogen, as well as too much testosterone, cortisol and aldosterone.
The Cleveland Clinic reports that too much estrogen in a woman can result in menstrual bleeding after the woman has gone through menopause and irregular menstrual periods in women who have yet to go through menopause.