Hormone replacement therapy is a treatment designed to replace some of the hormones that are reduced as a result of the menopause. According to U.K. health provider, Bupa, hormone replacement therapy usually combines two hormones, estrogen and progesterone; estrogen may be prescribed alone, however. Although hormone replacement therapy may be of benefit in reducing some of the signs and symptoms of the menopause such as hot flashes, mood swings and osteoporosis, taking hormone replacement for prolonged periods may pose significant health risks.
Cancer
According to the American Cancer Society, hormone replacement therapy may increase a woman's risk of developing various cancers. Estrogen-only hormone therapy may be associated with an increased risk of endometrial cancer. According to findings from a clinical study, one in nine women treated with estrogen-only therapy for 3 years developed pre-cancerous changes in the endometrium. Combined progesterone and estrogen use does not appear to carry the same risk for endometrial cancer; it does, however, increase the risk of developing breast cancer by 5 to 6 percent with each year of use, according to the American Cancer Society. Studies have also found that women who take estrogen-only therapy are at a higher risk for ovarian cancer than those who don't use hormone replacement therapy.
Heart Disease
Hormone replacement therapy may also increase the risk of heart disease. MayoClinic.com notes that it was once widely accepted that hormone replacement therapy helped protect the heart, but data from a clinical trial designed to assess the risks of hormone replacement therapy found that hormone therapy slightly increased the risk of heart disease. MayoClinic.com also notes, however, that this risk may be greater in some women than others and that the overall risk is low. Nevertheless, women who have a family history of heart disease should proceed with caution and speak to a doctor about any concerns, says MayoClinic.com.
Blood Clots
According to Medline Plus, taking estrogen-only hormone replacement therapy is known to be linked to an increased risk of blood clots. MedlinePlus states, however, that the risk is generally higher in women who have used birth control pills, because they contain high doses of estrogen. This risk may be heightened further in women who smoke. MayoClinic.com also notes that a large clinical trial designed to assess the risks posed by hormone replacement therapy found that over a period of one year, out of 10,000 women on combined hormone replacement therapy, 18 or more experienced a blood clot.
