THURSDAY, Nov. 1 (HealthDay News) -- Hypnosis may help reduce hot flashes in postmenopausal women, cutting down their frequency as much as 74 percent, researchers say.

Hot flashes affect about 80 percent of women as they go through menopause. The sudden rush of heat can be followed by chills and can reduce quality of life.

Researcher Gary Elkins, director of the Mind-Body Medicine Research Laboratory at Baylor University in Waco, Texas, assigned 187 women who had at least seven hot flashes daily to either five weekly sessions of clinical hypnosis with at-home practice or a comparison treatment called structured attention.

Women self-reported their hot flashes for 12 weeks, and the researchers also measured hot flash frequency by a skin conductance monitor.

"Our results indicated both a reduction in perceived hot flashes and physiologically verified reduction in hot flashes over three months," Elkins said.

The study was published online Oct. 22 in the journal Menopause.

Women in the comparison group met once a week for five weeks with a clinician. They discussed symptoms, avoided negative suggestions, and were given a recording with information about hot flashes that they were told to listen to daily.

Those in the hypnosis group received five weekly sessions with a clinician versed in hypnosis. They were given suggestions for mental images of coolness, a safe place or relaxation, and picked the one they wanted to use. In addition, they were given an audio recording of a hypnotic induction to practice daily.

After 12 weeks, the hypnosis group reported 74 percent fewer hot flashes, while the comparison group reported 17 percent fewer.

The study was funded by the National Center for Complementary and Alternative Medicine of the U.S. National Institutes of Health.

In the wake of the Women's Health Initiative study results, released in 2003, which found increased health risks such as heart disease with long-term hormone therapy use, many women are seeking non-hormonal alternatives for hot flash relief. In a previous study, Elkins had found that hypnosis helped breast cancer survivors reduce hot flashes by nearly 70 percent.

One drawback, Elkins said, is the lack of people with training in hypnosis for hot flashes. He hopes to develop a CD or DVD program.

Meanwhile, women can get referrals from the American Society of Clinical Hypnosis and the Society for Clinical and Experimental Hypnosis, he said.

Costs vary. Elkins estimates an initial visit is about $170, and follow-ups about $135.

No adverse effects were reported, Elkins noted, except for temporary irritation from the skin conductance monitors used to verify hot flashes.

The nearly 75 percent reduction ''is a very good result," said Dr. Margery Gass, executive director of the North American Menopause Society and a consultant at the Cleveland Clinic. She reviewed the findings.

The most likely drawback to using hypnosis for hot flashes, she said, is the effort required. Initial training must be given by a health care professional versed in hypnosis, she said, "and then you have to practice at home."

Experts don't know exactly how hypnosis may work to cool the hot flashes. Gass said it probably affects the body's thermostat regulation in the brain.

More information

To learn more about hypnosis, visit the American Society of Clinical Hypnosis.