(FORTUNE Magazine) – One of my patients, a 48-year-old woman, recently complained of having difficulty sleeping. She was also experiencing wild mood swings and hot flashes. She was convinced she was suffering from a rare, probably fatal disease. I assured her she wasn't. She was experiencing menopause.

Menopause usually occurs when women are in their mid-40s to mid-50s and their ovaries stop making estrogen. At the start of menopause, the ovaries actually short-circuit, sometimes producing no hormones at all; at other times they send pulses of hormones screaming through the body. Symptoms may also include pain during intercourse; vaginal skin changes; and irregular, prolonged, or missed periods.

Years ago there wasn't much a woman could do except grin and bear it. Now there's an option: hormone replacement therapy (HRT), which generally involves replacing the missing hormones with a combination of estrogen and progestin.

In addition to dealing with the symptoms of menopause, HRT helps keep bones strong and decreases the risk of osteoporosis. HRT can keep skin healthy. It may even protect against Alzheimer's and colon cancer. While some studies suggest that it helps prevent heart disease, the Heart and Estrogen/Progestin Replacement study--which involved women who already had heart disease--surprisingly showed that the risk of recurrent heart disease increases in the year after starting HRT.

The benefits of HRT usually outweigh the risks, but those risks are far from negligible. Possible side effects include fluid retention, breast tenderness, mood swings, headaches, an increase in triglycerides (a type of blood fat), and a slightly increased risk of gall bladder disease and blood clots. The biggest potential risk is breast cancer, which increases with the duration of treatment. The risk of breast cancer also varies with the type of treatment, growing slightly when estrogen alone is used, a little more when the treatment involves a combination of estrogen and progestin.

All this needs to be kept in perspective, because the degree to which HRT increases breast cancer risk is not large. Other factors, such as a family history of breast cancer, play a greater role. And although the risk of developing breast cancer increases slightly from HRT, other studies suggest that the risk of dying from breast cancer may actually be lower in women on HRT. (Also, when used alone, estrogen has been known to increase the risk of uterine cancer; progestin protects against it.)

If a woman and her doctor decide that it's time to start treatment, there are a number of options. Most doctors recommend daily estrogen. For women who can't tolerate oral estrogen, a patch is available. Progestin can be taken intermittently or every day. The advantages of daily progestin are that it's easy to remember and continued periods are less likely. The disadvantage is that spotting can occur at any time of the month and may have to be investigated with a uterine biopsy.

The traditional strategy is to combine daily estrogen with progestin for ten days each month. That mimics the body's cycle, and most women continue to have menstrual periods, although they often ease with time. A new strategy: daily estrogen and a 14-day course of progestin every three to six months. This results in fewer periods but is still probably protective against uterine cancer. An even newer strategy involves smaller amounts of "micronized" progestin, a natural form of progesterone that doesn't adversely affect blood cholesterol. Women may even feel better on this agent, compared with other progestins. I think micronized progestin every three to six months is a promising option, but we'll need future studies before we can come to firm conclusions.

FOR MORE INFORMATION ON THIS TOPIC go to mayoclinic.com. Mayo Clinic offers Executive Health Programs at Mayo Clinics in Jacksonville, Fla.; Rochester, Minn.; and Scottsdale, Ariz.