The menopause is a natural event and hot flashes are the most common menopausal symptom. The intensity and frequency of hot flashes varies greatly from woman to woman. A hot flash is a feeling of warmth that spreads over the body, but is often most strongly felt in the head and neck regions. Hot flashes may be accompanied by perspiration or flushing. Hot flashes usually last from 30 seconds to several minutes. Although the exact cause of hot flashes is not fully understood, the most widely accepted theory is that hot flashes are caused by a deficiency in circulating estrogen as a result of declining ovarian function.