Although the average age for menopause is 51, women experience symptoms at varying ages. In fact, age 40 is still considered normal, according to the website FamilyDoctor.org. Hot flashes are one of the most common symptoms of pre-menopause and menopause, with three out of four women experiencing them. Several different situations can cause or trigger a hot flash in a woman at age 45.
Stress
When it comes to hot flashes, stress tops the list as one of the triggers. Women who have a difficult time coping with stress have more hot flashes, according to the September 2006 issue of "Menopause." In this study, women were taught to identify stressful situations and learn relaxation techniques, which resulted in a reduction of hot flashes. Many women find that once they become aware of what initiates the hot flash, they have a better chance to reduce the intensity.
Hot Rooms
Research at Columbia University in New York City indicated that women have fewer hot flashes in a cool room as opposed to a warm room. It appears that overly-heated rooms can trigger a hot flash, according to the website ChicagoHealers.com. A warm room can be a contributing factor to hot flashes at night, commonly called "night sweats."
Spicy Foods
Spicy foods often cause a woman to experience a hot flash, as reported by "Fox News" Health Blog. Avoiding those hot, spicy foods during this time of hormonal change may reduce the incidence of hot flashes. Many women find they can return to eating these spicy foods after menopause.
Smoking
Women who smoke have more hot flashes, according to the website MayoClinic.com. Smoking should be eliminated for a better transition to menopause.
Hot Drinks
Hot drinks, similar to hot spicy foods, are also known to trigger a hot flash in some women, according to women's specialist Dr. Christiane Northrup. Although not all women will respond this way, it is important they are aware of the possibility that hot drinks trigger a hot flash.


