When a women reaches menopause, the levels of estrogen in the body decrease, which can cause symptoms like hot flashes, mood swings, confusion and vaginal dryness, according to the Hormone Foundation. Physicians can prescribe hormone replacement therapy with estrogen and progesterone to replace the diminished levels and relieve some of the symptoms. However, a large clinical trial called the Women's Health Initiative--which evaluated 27,000 women--found that hormone replacement therapy carried significant health risks that may outweigh the benefits of using the treatments for some patients. Women should discuss the potential risks with their physicians when making the decision to use hormone replacement therapy.
Heart Disease
For women taking hormone replacement therapy containing estrogen and progesterone, there is an increased risk of heart attacks, according to the Ohio State University Medical Center website. This increased risk was found in both healthy women and those women with previous cardiovascular disease. The researchers in the Women's Health Initiative did not find an increase in risk of heart attacks for women who only took estrogen only.
Increased Risk of Breast Cancer
Hormone replacement therapy can increase the risk of developing breast cancer, according to the MayoClinic.com. During the study, the risk of developing breast cancer in an individual woman was not very large but did begin to increase after 3 years of continuous combined therapy, according to the Hormone Foundation. But because of the large numbers of women who might be taking hormone replacement therapy, the total number of women who might develop breast cancer was much higher. The risk also appears to go back to normal within five years of discontinuing hormone replacement therapy, according to the National Health Service. Women who took estrogen-only hormone replacement therapy did not show an elevated risk of breast cancer.
Increased Risk of Stroke
Combined estrogen and progesterone hormone replacement therapy can also increase the risk of stroke in both healthy women and women who have cardiovascular disease, according to the ProjectAWARE website. Women who took estrogen alone also had an increased risk of stroke as well, according to the MayoClinic.com. This may be associated with the increased risk for formation of blot clots while taking hormone replacement therapy, according to the National Health Service.
Increased Risk of Ovarian Cancer
According to the American Cancer Society, combined hormone replacement therapy may slightly increase the risk of developing ovarian cancer. Ovarian cancer is a rare type of cancer so even with the small amount of increased risk, the overall risk of developing ovarian cancer is still low. The risk of ovarian cancer in women who take estrogen-only hormone therapy is slightly elevated as well. This risk increases the longer the hormone replacement therapy is taken, according to the National Health Service.
Increased Risk of Blood Clots
Both combined and estrogen-only hormone replacement therapy can increase the risk of blood clots in the legs, according to the MayoClinic.com. The inclusion of estrogens may be the cause of the increase in blood clotting, according to the ProjectAWARE website.
