#What causes Hot Flashes?

The hypothalamus, located deep in the midbrain, is your body's thermostat. Along with the Autonomic Nervous System (ANS), it controls blood vessel dilation & constriction. The hypothalamus needs estrogen to function properly. A lack of estrogen affects the feedback system between the hypothalamus & the ANS, thereby disrupting these two temperature regulators. So during perimenopause & menopause, the lack of estrogen & it's deficiency respectively, causes the hypothalamus to change it's thermostat set point, signalling the ANS to dilate the surface blood vessels and release some heat. So what does this mean? Due to the fluctuating concentration of estrogen in this stage of life, you basically have no control over when you're body acts as a heat exchanger!