Perimenopause, or menopause transition, is the stage of a woman’s reproductive life that begins several years before menopause, when the ovaries gradually begin to produce less estrogen. It usually starts in a woman’s 40s, but can start in a woman’s 30s or even earlier.

Perimenopause lasts up until menopause, the point when the ovaries stop releasing eggs. In the last34 one to two years of perimenopause, this decline in estrogen accelerates. At this stage, many women experience menopausal symptoms.

Premenopause, often referred to as perimenopause, is the phase in a woman’s life just before the onset of menopause, which is when a female’s menstrual cycle permanently ceases. The average age for a woman to begin experiencing premenopausal symptoms is 45, but women as young as 25 and as old as 70 can also exhibit signs of premenopause. The length of premenopause varies from woman to woman, but typically lasts from one to six years.

During premenopause, a woman’s hormone production begins fluctuating and declining, which can cause a wide variety of symptoms. A majority of premenopausal women experience changes in their menstrual cycle. As a woman’s estrogen levels begin to decline, the menstrual cycle may shorten, causing more frequent periods. However, some women begin to have longer cycles and less frequent periods. Some women even skip periods. Despite these menstrual changes, a woman is not considered truly menopausal until she has had no period for twelve consecutive months.

In addition to menstrual cycle changes, the drop in estrogen levels during premenopause can cause a host of other physical symptoms, such as hot flashes, night sweats, weight gain, headaches, vaginal dryness, breast tenderness, and sleep problems. Premenopause can also trigger a variety of emotional changes, including anxiety, irritability, depression, and a sudden inability to handle stress.