Hot flashes, caused by hormonal imbalances, can last for as long as the hormones are out of balance. I used to work for Women to Women's home program several years ago. One of the things I learned about hot flashes is diet and stress contribute in a big way to the imbalance. But specifically, the main triggers to hot flashes are: caffeine, stress, high simple carbs, and hot temperatures. We always recommended a diet where you always ate the 3 macro-nutrients together - carbs, fats, and protein. Always eat whole foods, including full fat foods (which actually work as amazing appetite suppressants), and keep your carb intake to 15 grams/meal, 7 for your snack. If your are very active, you can raise that somewhat. And remember, certain vegetables and of course fruits are considered carbs. So, tracking when you have a hot flash and reflecting on what's going on in your life as well as your diet (did you just have soda (diet sodas sometimes make it worse)) can go a long way to helping you take control of the hot flashes.