Peri menopause means literally "around menopause" and is a transitional stage of two to ten years before complete cessation of the menstrual period. Peri menopause usually appears in women from 35 to 50 years of age. This stage of menopause is characterized by hormone fluctuations, which cause the typical menopause symptoms like menstrual irregularity.
Peri menopause is defined as the transitional time between the first irregular menstrual periods to the last one. As seen in the previous chapter (premenopause) the “normal” menstrual cycle is the hormonal balance between estrogen, progesterone, FSH and LH. The fluctuations of these hormones cause the symptoms of perimenopause.
The follicles remaining in the ovaries of a peri menopausal woman get less sensitive to stimulation of FSH, than they were during the child bearing age. There will be occasionally abnormal cycles, in which the follicle does not develop fully.
When a follicle does not develop properly, it secretes less estrogen and the FSH levels rise. Sufficiently low estrogen levels may fail to trigger the LH surge, which is supposed to rupture the follicle. Consequently the egg isn't released and there will be a cycle without ovulation. This is termed an anovulatory cycle.
During this, progesterone cannot be released at the appropriate time and the lack of estrogen gives rise to all the familiar peri menopause symptoms.
In perimenopause the number of such abnormal cycles without a mature follicle increases. Finally there will be cycles in which no follicle develops at all.
The decline of progesterone and estrogen results in a general shortening of the length of the cycles. These irregular cycles are often the first signs that peri menopause has started.
These hormonal fluctuations vary from woman to woman and consequently each woman get to know peri menopause differently. It is said, that a woman usually mimics her mother's experience, but no woman can predict which symptoms she will experience, or when she will experience them. Pregnancies, birth control pills, the age a woman began to menstruate or breast-feeding have no impact on the beginning of peri menopause. The only reliable factor is smoking. If a woman smokes, she can count on starting 1-2 years earlier into peri menopause than women who don't.
In summary, peri menopause can best be described as the time when a body gets ready for menopause.