Hot Flashes Linked to Insomnia
Severe Hot Flashes, Chronic Insomnia Often Go Together, Study Shows
WebMD News Archive
June 26, 2006 -- Women who have severe menopausal hot
flashesoften have chronic insomniaas
well, a new study shows.
The study, published in the Archives of Internal Medicine, comes
from Maurice Ohayon, MD, DSc, PhD, of Stanford University's medical school.
"Severe hot flashes are strongly associated with chronic insomnia in
midlife women," writes Ohayon, who recommends asking women with chronic
insomnia about hot flashes and possibly treating hot flashes to improve sleep
About Hot Flashes
Hot flashes are a common symptom of menopause. Up to 85% of menopausal women
experience them, according to background information cited in the study.
Data for Ohayon's findings came from 982 California women age 35-65 years.
Ohayon split the women into three groups:
- Before menopause (premenopausal): 562 women
- Around the time of menopause (perimenopausal): 219 women
- After menopause (postmenopause): 201 women
Menopause doesn't happen overnight. Here's what those terms mean in this
- Premenopause: Women at least 35 years old who reported regular menstrual
periods in the last year.
- Perimenopause: Women who reported irregular
menstrual periods during the last year and had at least one period in the
- Postmenopause: Women who reported no menstrual bleeding during the last 12
During telephone interviews, the women were asked if they had hot flashes.
They also rated their hot flashes' severity by these standards:
- Mild: Hot flashes usually don't cause sweating.
- Moderate: Hot flashes usually include sweating that doesn't limit
- Severe: Hot flashes usually cause sweating that prompts a woman to stop her
The women also reported any sleep problems. Chronic insomnia was defined as
at least six months of poor quality sleep, including trouble falling asleep or
Severity of Hot Flashes
Nearly a third of the women reported having at least three weekly hot
flashes in the previous month. About 12% of the premenopausal group, 79% of the
perimenopausal group, and 39% of the postmenopausal group reported having hot
flashes that often.
Of the women with frequent hot flashes, about half experienced mild hot
flashes and nearly one-third had moderate ones. But 15.5% said they suffered
from severe hot flashes, Ohayon writes.
Like hot flashes, chronic insomniawas
most commonly reported by perimenopausal women, followed by the postmenopausal
More than half of the perimenopausal women had chronic insomnia (nearly
57%). So did about half of the postmenopausal women (almost 51%).
Chronic insomnia was rarest among premenopausal women, the study shows.
Hot Flashes and Sleep
Many health problems can disrupt sleep. Ohayon took that into account.
Self-reported poor health, chronic pain, and sleep
apnea(in which breathing stops
temporarily during sleep) were tied to chronic insomnia. After considering
those factors, Ohayon still found a strong link between severe hot flashes and
Of the 48 women who experienced severe hot flashes, about 80% had problems
with chronic insomnia.
The women weren't followed over time. But more than half of the
perimenopausal women and one in five postmenopausal women said their chronic
insomnia began before, not during, menopause.
Even so, Ohayon found that "chronic pain and moderate or severe hot
flashes were associated with chronic insomnia occurring around or after
"Treating hot flashes could improve sleep quality and minimize the
deleterious consequences of chronic insomnia," Ohayon writes.
However, Ohayon's study didn't test any treatments for hot flashes.
The study was partly funded by NV Organon, which makes hormone therapies for