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Hot Flashes

August 10, 2011

A listener asks: What causes hot flashes?



The how of hot flashes…I’m Bob Hirshon and this is Science Update.

Laura, a listener from Takoma Park, Maryland, wants to know what causes the uncomfortable flushing of hot flashes. We asked Dr. Robert Freedman of the Wayne State University School of Medicine, a founding member of the North American Menopause Society. He says the body regulates temperature like a thermostat, maintaining a neutral zone in which a person doesn’t feel too hot or too cold. But in women undergoing menopause, this neutral zone is very narrow. So a small increase in temperature triggers the body’s cooling mechanisms.

ROBERT FREEDMAN (Wayne State University):

Your blood vessels dilate rapidly to increase blood flow, mainly in the arms and legs and hands and feet and forehead, to dissipate heat, thereby lowering your core body temperature. It acts like a giant radiator.


Freedman says the drop in estrogen levels during menopause is necessary for hot flashes to occur but doesn’t completely explain what causes them. I’m Bob Hirshon, for AAAS, the science society.