For more than 70 percent of women, hot flashes are inconvenient and sometimes unpleasant reality of menopause.
The symptoms seem to begin in the hypothalamus, the part of the brain that helps regulate body temperature. Hormonal changes may cause the hypothalamus to tell the body it's really hot. As a result, the body responds with such things as sweating and dilated blood vessels – reactions that usually occur when the body is actually experiencing extreme heat.
But it's not really clear what triggers this process, how to stop it and even whether a lack of estrogen, the female sex hormone that declines in middle age, is its cause.
Options for attempting to relieve hot-flash symptoms include traditional hormone replacement therapy, or HRT, and bioidentical hormone therapy, which mimics hormones produced by ovaries using plant or animal derivatives.
Self-management is another approach, for which the National Institute on Aging recommends dressing in layers, carrying a portable fan, maintaining a healthy weight and trying mindfulness techniques to ease discomfort.
HRT was common until about 15 years ago, when a major trial suggested it increased women's risk of heart disease and some breast cancers.
A recent study suggests that five to seven years of traditional hormone therapy may be safe – for certain groups of women. The study found that women who take HRT for up to seven years had no greater mortality risk than women who did not.
It's unclear whether HRT will come back into fashion. Most medical associations recommend that women who choose it take the lowest dose possible for the shortest time possible.