Q: How do I decide if hormone replacement therapy is right for me?

A: For women approaching or experiencing menopause -- the average age that women enter menopause is 51 -- preventive medicine to reduce their risk of disability from conditions requiring long-term treatment is significantly important because of the increased health risk factors common to this age group: specifically cardiovascular disease and osteoporosis. Cardiovascular disease is the leading cause of death in women over age 50, and bone fractures are a major cause of long-term disability and mortality as well.

The classic signs and symptoms of menopause -- hot flashes, irritability, depression, insomnia, vaginal dryness, sexual dysfunction and urinary incontinence -- are caused by estrogen deficiency. HRT with estrogen relieves most of these symptoms. The most significant benefit of HRT, however, is estrogen's positive effect on bone loss and cardiovascular disease.

Studies have shown that HRT has been associated with a 35 percent reduction in relative risk of death from coronary heart disease, and a recent analysis found a 25 percent decrease in the relative risk of suffering a hip fracture for women over age 50 who have ever used estrogen.

HRT is not recommended for women who have certain medical conditions, including unexplained vaginal bleeding, active liver disease, breast cancer or active vascular thrombosis (blood clots). Other conditions that may preclude HRT include gallbladder disease, a history of uterine cancer, chronic liver disease and a history of thromboembolism (blockage of a blood vessel by a fragment from a blood clot elsewhere in the circulatory system).

One of the major risks of HRT is the possibility of developing cancer of the lining of the uterus (endometrium), not cancer of the cervix. This risk is almost completely abolished by adding the hormone progesterone to the HRT. The risk of developing breast cancer while on HRT remains controversial; however, there appears to be an increased risk of developing cancer of the breast after HRT has been used for more than 15 years.

Common side effects of HRT include breast tenderness, nausea, vaginal bleeding and premenstrual syndrome-like conditions. About 20 percent of patients who do not receive proper counseling and information will stop HRT after 10 months of use. Women who have had hysterectomies are more likely to continue HRT, since the most common side effect of bleeding and the fear of cancer of the uterus are no longer an issue.

In deciding whether to begin preventive HRT, a woman and her physician should consider the following: the woman's risk factors for cardiovascular disease (family history, blood pressure, weight, smoking status, cholesterol levels), osteoporosis (women who are older, white, slender, sedentary, or have had an early menopause are at greater risk) and breast cancer (including personal or family history, childbirth after age 30 or menopause beginning after age 50); her desire for relief from symptoms of menopause; her tolerance for the side effects of HRT; and her willingness to participate in routine follow-up monitoring (such as mammography and endometrial cancer screening).

Hector C. Streeter, M.D., assistant professor of obstetrics and gynecology, The University of Arizona College of Medicine and obstetrician/gynecologist, The University Physicians North Hills Center