How long do hot flashes last? It used to be said that menopause-related hot flashes fade away after six to 24 months. But for many women, hot flashes and night sweats often last a lot longer—by some estimates seven to 11 years. The hormonal roller coaster that comes as a woman’s childbearing years wind down can trigger a range of hot flash symptoms. As many as 80% of women going through menopause experience hot flashes. Hot flashes, also known as vasomotor symptoms, are often described as a sudden sensation of heat in the chest, face, and head followed by flushing, perspiration, and sometimes chills. Hot flashes and sweats that occur during sleep can make it hard to get a good night’s rest. The estimates of the duration of these symptoms come from the Study of Women’s Health Across the Nation (SWAN), a long-term study of women of different races and ethnicities who are in the menopausal transition.