Why do hot flashes cause the skin to flush and sweat?

Hot flashes occur during menopause because declining estrogen levels interfere with the brain’s ability to regulate body temperature. As estrogen levels drop, the hypothalamus—the body's temperature control center—becomes overly sensitive.1

This sensitivity triggers sudden autonomic nerve activation, which the body perceives as a need for rapid cooling. To dissipate heat, the body initiates two primary physiological responses:21

• Vasodilation: The blood vessels supplying the skin dilate (widen), which increases blood flow to the surface and causes the characteristic flushing or blushing.21
• Sweating: The body stimulates perspiration to further assist in cooling the skin.21

These reactions are essentially the body's attempt to lower its internal temperature in response to a perceived, though not necessarily actual, state of overheating.1