Women who undergo hormone replacement therapy (HRT) often report a dramatic improvement in their quality of life due to a reduction of symptoms typically associated with menopause. According to the Food and Drug Administration (FDA), HRT is the most effective treatment for the following conditions related to menopause:

• Hot flashes
• Vulvar or vaginal atrophy

In addition, HRT is an option for preventing osteoporosis (thinning of the bones) in women whose risk of the disease outweighs the risk of treatment. HRT can reduce the amount of calcium lost from the bones. Women will usually receive the most effective protection against osteoporosis if they begin HRT around the time of menopause and continue to use it indefinitely.

Other non-estrogen drugs that can be used to prevent osteoporosis include bisphosphonates (such as alendronate and risedronate) and selective estrogen receptor modulators (such as raloxifene). However, these drugs are relatively new, so their long-term effectiveness is unknown.

Many women report that HRT is effective at relieving other symptoms associated with menopause, including:

• Sleep disturbances
• Depression
• Pain during intercourse
• Urinary tract infections

However, HRT also carries serious risks for some patients. These include increased risk of certain illnesses, such as:

• Blood clots
• Breast cancer
• Dementia
• Gall bladder disease
• Heart attack
• Ovarian cancer
• Strokes
• Uterine cancer
• Uterine fibroids

Women who still have their uterus while undergoing HRT have a greater risk of developing endometrial cancer (cancer of the uterine lining). Adding progestin lowers this risk. In addition, not only does use of HRT drugs raise the risk of breast cancer, but it also makes tumors harder to detect, which can lead to dangerous delays in diagnosis.

A follow-up study to the Woman’s Health Initiative (WHI) found that the combination of estrogen and progestin increases the risk of dementia in women 65 years and older while failing to prevent memory loss. However, women who start HRT earlier in life -- before they turn 65 -- could reduce their risk of developing Alzheimer’s or dementia, according to a new study.

Common side effects associated with HRT include:

• Headache.
  
• Breast pain or tenderness. Women who develop this side effect while using HRT may be forming denser breast tissue, according to recent findings. Studies have shown that women with denser breasts are at higher risk for developing breast cancer.
  
• Irregular vaginal bleeding or spotting.
  
• Stomach cramps.
  
• Nausea and vomiting.
  
• Hair loss.
  
• Skin discoloration.
  
• Dizziness.
  
• Fluid retention.
  
• Mood changes.

Side effects can be reduced by taking the lowest possible effective dose of the hormone for the shortest period of time possible. In some cases, patients may find relief from side effects by switching to an alternative form of HRT.

In recent years, the benefits and risks of HRT have been studied in depth. Initially, HRT was believed to help prevent cardiovascular disease in older women. However, the WHI study completed in 2002 revealed that HRT may not protect women from heart disease. In addition, findings indicated a slight increase in the risk of breast cancer, blood clots, stroke and heart attack.

Although HRT may not help prevent heart disease in older women, the therapy may be beneficial for younger postmenopausal women. New results of the WHI Estrogen-Alone Trial show that younger postmenopausal women -- age 50 to 59 -- who take estrogen-alone hormone therapy have significantly less buildup of calcium plaque in their arteries compared to women who do not take hormone therapy. Coronary artery calcium is a known risk factor for heart disease. However, experts caution that the heart disease effects of HRT remain unclear.

Despite the potential risks, it should be emphasized that the likelihood of adverse effects due to HRT remains low in most women. The risks also gradually decrease in the years after a woman stops HRT. According to the FDA, for every 10,000 women taking HRT, there are:

In addition, postmenopausal women taking progestin as part of HRT may experience greater hearing loss than women taking estrogen alone or no hormones at all, according to a recent study.

It should be noted that the health risks associated with HRT (e.g., heart disease) can vary with age and the health of a woman. Women need to discuss the risks and benefits of using HRT with their physicians to determine the best course of treatment following menopause.