Menopause occurs when a woman’s periods stop permanently as the result of loss of estrogen. Natural menopause most often begins when a woman is in her 50s and her ovaries have stopped producing estrogen. Medical menopause occurs when medication or surgery suppresses or eliminates ovarian function. The result is the same: loss of estrogen leading to significant body changes.

Estrogen is responsible for many bodily functions, including the body’s natural thermostat, bone health, libido and sexual function, cardiovascular fitness, and metabolism. So when estrogen levels drop during menopause, many women experience such changes as hot flashes, night sweats, decreased libido, vaginal dryness, weight gain, hair thinning, and depression.

Hormone replacement therapy (HRT) is estrogen-containing medication designed to replenish estrogen stores and limit or eliminate menopausal symptoms. It is very effective at relieving the uncomfortable symptoms that a menopausal woman experiences, which improves quality of life.

If the patient’s uterus is present, the HRT must be a combination HRT, consisting of both estrogen and progesterone, to protect against endometrial cancer (cancer of the uterine lining). If the uterus is absent (in other words, if a woman has had a hysterectomy), estrogen alone is prescribed.

Women have been taking HRT for decades, however we now know that all forms of HRT pose significant health risks. Each woman must be aware of the following risks and discuss them with her doctor.

Although a woman’s native estrogen keeps her heart healthy, it appears that the estrogen in HRT does not. In fact, it appears to promote other vascular diseases, such as venous thromboembolism (clots in the veins that may travel to the lungs) and stroke (diminished oxygen supply to the brain), which can be sudden and fatal.

Evidence has also shown that combination HRT increases the risk of breast cancer. Moreover, combination HRT seems to be associated with breast cancer that has a poorer prognosis—cancer that is more likely to recur or to present with distant disease. The good news is that once a woman stops the combination HRT, the risk of breast cancer begins to decline. A woman who has not used combination HRT for 5 years or more has essentially the same risk of breast cancer as a woman who never took that medication. HRT that only contains estrogen does not influence breast cancer risk; however, it is still associated with venous thromboembolism and stroke.

If you have menopausal symptoms, it is important to discuss them with your doctor and consider the risks and benefits of taking HRT. Your personal and family history must also be taken into account. If you have a personal history of cardiovascular disease or breast cancer, HRT would not be advised.

If you are prescribed HRT, it is strongly recommended that you take the minimum dose for the shortest period of time necessary to relieve your symptoms. This may mean taking the lowest strength and/or taking the medication only a few times a week instead of daily. Doing so can reduce the risk of diseases, but it does not eliminate the danger. Regardless of the dose and frequency, your ultimate goal should be to completely stop HRT.