Hot flashes are the most common symptom of menopause. Although hot flashes can be triggered by internal and external influences, such as stress, excitement, spicy foods or even room temperature, their exact cause is unknown. The current theory is that neurons in the body's central thermoregulation system in the hypothalamus may act differently when exposed to the low estrogen environment of menopause, causing the body to flush. If the hypothalamus mistakenly senses that you are too warm, it starts a chain of events to cool you down. Blood vessels near the surface of the skin begin to dilate (enlarge), increasing blood flow to the surface of the skin to try and dissipate body heat. This produces a red, flushed look to the face and neck in light-skinned women. It may also cause you to sweat (sometimes sweating excessively) to try and cool your body down. An increased pulse and a feeling of momentary high heart rate may also occur.