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It has become usual to refer to all the changes that take place at the end of a woman's fertile time as 'menopause'. In fact the word menopause simply means 'the last menstrual period', and no one can say when this is until a year has passed since that last period.
Once a year has passed after the last menstrual bleed, a woman can say her menopause was on that date. Any subsequent bleeding is not considered normal, and a thorough investigation is advisable.
The proper name for the period of about five years around the time of the last menstrual bleed is 'the climacteric'. This term covers the time when women's hormone levels fluctuate and many can experience problems as their bodies adapt.
Ovaries And Periods
During the reproductive years, most women's ovaries release one or two eggs per month, and this regular ovulation takes place under the control of the menstrual cycle.
As menopause approaches, your menstrual cycle will usually change. A very few women just stop having periods without the cycle length changing in some way. But for most women periods become heavier or sparser, or stop and start over a few months. Not all women's periods are the same, but all are considered normal as long as they happen fairly regularly and the bleeding lasts from two to eight days (usually about four to six days).
The average cycle length is 28 days, but anything from 21 to 36 days is still considered normal. Your menstrual cycle may change throughout the course of your life, with many outside factors affecting it, including illness, contraception methods, weight gain or loss, stress or pregnancy.
To fully understand what changes your body goes through in the time leading up to menopause, it is important to grasp just how your monthly cycle has been controlled and what exactly your ovaries have been doing.
What Has Been Going On?
Every month at the beginning of your menstrual bleed, the area of the brain called the hypothalamus detects low estrogen levels and sends a signal, via gonadotropin-releasing hormone, to another area of the brain, the pituitary. The pituitary in turn signals to the ovaries by releasing follicle-stimulating hormone (FSH) and Latinizing hormone (LH).
FSH stimulates around 10-20 ovarian follicles to begin maturing. Usually only one or two will become mature ova ready for fertilization. The others degenerate and are reabsorbed.
The developing follicles release the hormone estrogen, which in turn acts on the lining of the uterus, causing it to grow and thicken. This first phase of the menstrual cycle is called the follicular phase.
When one of the follicles is ripe enough, estrogen levels in the blood reach a peak, signaling to the pituitary to release LH. This acts on the ripe follicle to cause ovulation and the release of the mature egg, as well as production of the hormone progesterone. The egg is released from the follicle in the ovary and is drawn into the funnel-shaped end of one of the fallopian tubes, where it starts its journey to the uterus.
Most women do not notice when they ovulate, but a few notice a slight abdominal twinge or cramp known as Mittelschmerz or 'middle pain'. Some women notice that they feel most in the mood for sex around the time of ovulation. The subsequent phase is called the luteal phase, when the ovary makes both progesterone and estrogen, and is usually a constant 14 days in length. In the time leading up to menopause it is this phase in the cycle that becomes erratic, as egg quality and quantity decline and ovulation may not be taking place at all.
During the luteal phase, the follicle that released the egg forms a corpus luteum, or yellow body, and produces progesterone. This hormone prevents other follicles from developing and keeps the lining of the uterus prepared in case the egg is fertilized and pregnancy occurs. It takes a few days for the egg to travel down the fallopian tube to the uterus, and it is during this time that the egg may become fertilized if there are sperm present.
If fertilization, or conception, does not take place, the corpus luteum degenerates and disappears, and the progesterone and estrogen levels fall. The uterine lining starts to disintegrate and finally is shed as a menstrual bleed. The low hormone levels feed back information to the hypothalamus in the brain, and the whole cycle starts again.
As We Get Older
As early as age 35 the egg follicles may stop ripening in a predictable way, and even if regular menstruation occurs, not all cycles will involve ovulation, and therefore not all cycles will have the usual rise in progesterone to follow the rise in estrogen. The estrogen levels become lower as fewer egg follicles grow and ripen, and if none mature enough to be released no corpus luteum is formed to produce progesterone. This means that the uterus builds up a thick lining in response to estrogen but no progesterone is released. The endometrial lining of the uterus gets thicker and thicker and when menstruation occurs there can be heavy bleeding.
The cycle will probably be longer or shorter than usual. The first sign of the perimenopause is nearly always a change in the menstrual pattern. The very first sign of ovarian decline is a shortening of the cycle. Most women have a shorter cycle in their early 40s than they did in their 20s. Subsequently, around the perimenopause they experience longer cycles and less bleeding. Some have longer cycles and then very heavy bleeds, and others continue with the shorter cycles but with very short, scanty periods - and the unlucky ones get short cycles and very heavy bleeds.
Common Questions About Menopause |
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