Estrogen treatment can offer relief from symptoms of menopause. But women and doctors worry about its ties to other conditions.

Encyclopedia: What Is Menopause?

A new study in the Journal of the American Medical Association says, however, that it does not add to heart risks in women within 10 years of menopause.

"These findings are somewhat reassuring to younger women who want to use hormone therapy for relief of severe hot flashes and night sweats because of no increased risk of coronary heart disease and a trend toward a reduced risk of total mortality," said Dr. Jacques Rossouw of the National Heart, Lung and Blood Institute.

His study found that older women who still have symptoms of menopause after 10 years -- something that only happens about 10 percent of women -- have the greatest risk of heart disease.

"There is something about hot flashes and night sweats at an older age which are linked to higher risk and this risk is then further increased if those women take hormone therapy," he said.

There was particularly good news for younger women who take estrogen only.

"We found that estrogen plus progestin is worse for your heart health than estrogen only. For stroke, it didn't matter. Both estrogen plus progestin and estrogen only increased the risk of stroke."

Because of that stroke risk -- and the increased chances of breast and uterine cancer -- women on hormones need to check their blood pressure and have regular mammograms.

The benefits of the treatment sometimes make it worth the risks.

"There remains legitimate indications for using hormone therapy," Rossouw said.