Perimenopause is the span of years before menopause when a woman's hormone levels and menstrual periods become irregular. Perimenopause has been described as "going through menopause" or "being in menopause."

After 1 year of having no periods, a woman has reached menopause. This is usually around age 50. In the years before menopause, changing hormone levels, particularly estrogen and progesterone, cause perimenopausal symptoms. These typically start in a woman's mid-40s, and they continue for a year or two after menopause.

Some women have mild perimenopausal symptoms. Others have severe symptoms that affect their sleep and daily lives. Symptoms can include:

• Unpredictable changes in menstrual pattern, including heavier or lighter blood flows and shorter or longer cycles.
• Hot flashes.
• Night sweats and sleep problems (insomnia).
• Memory problems and lack of concentration.
• Depression.
• Anxiety, irritability, and mood swings.
• Heart palpitations.
• Vaginal itching or dryness, causing discomfort during sexual activity.
• Decreased sex drive (libido).