Perimenopause - What Is Menopause: Menopause

Content provided by the Faculty of the Harvard Medical School

Perimenopause

Estrogen doesn't disappear suddenly. Even though women don't reach menopause until an average age of 51, the effects of declining estrogen may be noticeable as early as age 35 in the form of decreased fertility and irregular periods. This time of early symptoms — caused by hormonal changes related to aging ovaries — is known as perimenopause.

Perimenopause varies greatly from one woman to the next. It may last only a few months or several years. Symptoms may be mild or severe. Only a small percentage of women have no symptoms at all. The earliest sign of perimenopause may be declining fertility; for someone planning a pregnancy, this can be a major issue. Even for those who aren't planning a pregnancy, early symptoms of menopause such as fluctuating periods (see Figure 2) or hot flashes well before age 50 can be bewildering.

Figure 2: The ups and downs of perimenopause If you've ever wondered why a woman's period becomes irregular or unpredictable during perimenopause, examine this graph, which charts six months of hormone levels for a perimenopausal woman. Instead of a precise monthly pattern (see Figure 1), hormone levels fluctuate unpredictably, producing an early period one month, an unusually heavy period the next, and perhaps none at all the following month.

How do you know whether irregular periods, hot flashes, or insomnia are caused by perimenopause or a medical condition? There is no reliable test to tell if you're entering perimenopause. Your doctor could measure your FSH level to see if it is elevated. You can also buy a kit at the drugstore to check your FSH level. But during perimenopause, estrogen levels rise and fall erratically, and so do FSH levels. Results from an FSH test may vary from day to day, so a single test won't provide you with a clear picture of what is happening. But a mildly elevated FSH level on the third day of your menstrual period appears to correlate with diminished fertility — a harbinger of menopause.

Even though there is no clear-cut test for perimenopause, you will probably notice when changes begin in your body. Is your menstrual cycle noticeably different in a consistent pattern from a few years ago? Is your cycle shorter or your flow heavier? Insomnia may also coincide with the hormonal fluctuations of perimenopause. Among women this age, other symptoms such as irritability and memory loss are common, although their relationship to menopause is not certain. The first appearance of some of these symptoms can be alarming for women who aren't aware that perimenopause can begin years in advance of menopause. Recognizing these changes as a normal part of aging will help you and your clinician manage them effectively and plan for a healthy future.

Last updated:	August 13, 2007