While up to 80 percent of women experience menopausal vasomotor symptoms (VMS) such as hot flashes and night sweats during the transition to menopause, new research suggests these symptoms may last years longer than previously thought.

More than half of the women in a study published in JAMA Internal Medicine experienced frequent VMS for more than seven years during the transition to menopause.

The duration of VMS varied significantly among ethnic groups and based on a woman’s stage of menopause progression.

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Women’s individual experiences with menopause can differ drastically. But this study adds to a growing body of research suggesting that the symptoms are far more disruptive and persistent for many women than doctors believed.

“The traditional [consensus] had been that hot flashes and night sweats only lasted a few years and that they didn’t have a major impact on women’s quality of life,” said Dr. JoAnn E. Manson, Dr.P.H, a professor of medicine at the Harvard Medical School and chief of the division of preventive medicine at Brigham and Women’s Hospital.

While the study was not designed specifically to help women reduce VMS, “our findings will help clinicians in understanding that VMS can last a long time and will help identify some characteristics of women for whom they will last longer,” said fellow study author Nancy E. Avis, Ph.D., a professor in the Department of Social Sciences at Wake Forest School of Medicine.

Menopause Experiences Different for Each Woman

Researchers analyzed data from the Study of Women’s Health Across the Nation (SWAN), a study of women from various ethnic backgrounds transitioning to menopause. The data were gathered between February 1996 and April 2013.

Of the nearly 1,500 women with frequent VMS (defined as occurring at least six days in the previous two weeks), researchers determined a median total VMS duration of 7.4 years.

Women who were premenopausal or early perimenopausal when they first reported frequent symptoms had the longest VMS duration at 11.8 years. They also had frequent VMS after their final menstrual period for about 9.4 years.

Women who were postmenopausal when their VMS began had the shortest duration of 3.4 years after a final menstrual period.

Among the ethnic groups identified in the study, African American women reported the longest VMS duration at 10.1 years.

They were followed by Hispanic women (8.9 years) and non-Hispanic white women (6.5 years).

Japanese and Chinese women reported the shortest duration of menopause symptoms, with median totals of 4.8 years and 5.4 years, respectively.

“A number of cross-sectional studies have shown that African-American women are more likely to report hot flashes than white women, and Asian women are less likely to report hot flashes,” Avis said. “Our study suggests that these patterns are also found for duration. We really don’t know why we see these differences, but they tend to be consistent.”

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Certain environmental factors were also shown to influence a woman’s VMS duration.

“The extent to which the symptoms are bothersome and affect quality of life also correlates with psychosocial factors,” Manson said.

Those factors include financial strain and a person’s level of education.

Greater perceived stress, greater sensitivity to symptoms, more depressive symptoms, anxiety, and younger age were all related to longer duration of VMS as well.

Reducing VMS for All Women

Women going through menopause have a number of options for managing symptoms that range from simple lifestyle changes to medical intervention.

Some women may just need to keep the thermostat down or avoid triggers such as spicy food, while others might opt for medication.

The study authors recommend hormone replacement therapy (HRT), a treatment in which women replenish the female hormones their bodies are no longer making.

However, HRT has been linked to an increased risk of ovarian cancer. As with any treatment for VMS, women should consult with their doctors to find the best course of action.

Read More: Hormone Replacement Therapy: Is It Right for You? »