How do hot flashes occur?

For 85% of women, menopause can really heat things up -- and not in a good way. Though the exact cause of hot flashes is unknown, scientists think the drop in estrogen triggers a malfunction in the area of the brain that regulates the body's thermostat. When this happens, the brain thinks the body is overheating and tells the nervous system to release body heat ASAP. The result for you is intense hot spells that can turn you red and drench you in sweat. The quicker you go through menopause, the more intense your symptoms are likely to be. Smoking, being overweight, stress, and not exercising all increase the likelihood of hot flashes and night sweats. The good news is, only 20% of menopausal women will have hot flashes that impair their quality of life, says JoAnn Manson, chief of preventive medicine at Brigham and Women's Hospital.