As you approach menopause, you may start having hot flushes (also known as hot flashes). About 75 percent to 85 percent of perimenopausal women get them. These flushes are the most common symptom of perimenopause.

A hot flush is a sudden feeling of heat that rushes to the upper body and face. The skin may redden like a blush. You may break out in a sweat. A hot flush may last from a few seconds to several minutes or longer.

Hot flushes can happen anytime - day or night. Those occurring during sleep, called night sweats, may wake you up and leave you tired and sluggish the next day. Even though hot flushes are a nuisance, are sometimes embarrassing, and may interfere with daily life, they are not harmful.