It's not unusual for women to experience hot flashes or night sweats that can occur up to eight years before menopause , or the last menstrual period. The first clinical sign of the onset of this peri-menopausal transition can be a change in their menstrual cycle interval. The interval from the start of one menstrual period to the next can become either shorter or longer. Hot flashes and menstrual changes are often the first signs that a woman is entering the peri-menopausal transition. However, forty to fifty percent of women have reported intermittent hot flashes or night sweats without any change in their menstrual periods.
Hot flashes can occur sporadically, and infrequently.
The typical hot flash is a feeling of being hot or stuffy in a room where there is no significant change in the temperature. This is followed by a reddening of the face and upper part of the body, a flush due to an increased blood flow to the skin. Associated with this is perspiration on the face and chest. The body reduces heat by perspiring, with the resulting evaporation leaving you with a cold sensation. The typical hot flash can last approximately one to two minutes and occur as often as once or twice an hour.