The hot flash is a vasomotor symptom caused by a change in brain chemistry. This chemical change is the result of an abrupt drop in the body’s production of estrogen. It works somewhat like the domino theory. The chemical changes in the brain affect the temperature control center in the hypothalamus gland, a part of the brain. The hypothalamus causes the release of hormones that direct a decrease in the body’s core temperature set point. That decrease, in turn, causes the dilation of the blood vessels of the skin and sweating as your body accustomed to its own set point begins working to reset its own thermostat. This entire disturbance makes you feel as if your internal thermostat has gone haywire.
My hot flashes usually began in the traditional way, starting just above my waist, and then spreading quickly upward to envelop my chest, back, neck, face, and scalp. They were infrequent, but brutal. Some women have as few as two or three per day, while others may have as many as fifty flashes per day. Some women are barely disturbed by their flashes; others feel debilitated by them. There are reports from women who had hot flashes for only a few months and from others who endured flashes for years. Stress, alcohol, caffeine, and even spicy food seem to set off a hot flash in some women. Some women report cold flashes, as well. Flashes can create âœthe thermostat warsâ in some households.