Strictly speaking, the term menopause does not refer to a process but simply to the very last menstrual cycle of a woman’s reproductive life.
Perimenopause refers specifically to the transitional period between normal reproductive cycles and the final menstrual flow. Postmenopause refers to the years following the last period. For the sake of simplicity, however, we will use the word menopause to refer to the entire transitional time surrounding the end of a woman’s reproductive cycles.
When a woman approaches her fifties (and sometime earlier), the ovaries supply of eggs (or ova) becomes depleted. At the same time, they begin to reduce their production of estrogen and progesterone, the hormones that prepare the uterus for implantation of a fertilized egg. Essentially, the ovaries “retires” from their thirty to forty-year career of supplying eggs and hormones, although lesser amounts of various hormones are still manufactured. This may occur rapidly or over several years, during which time a number of important physical and emotional changes occur in a woman—not the least of which is the loss of her fertility.
The cessation of menstrual cycles is usually gradual, marked by increasing length of cycles. 70 percent of all women will experience such irregularity, with thirty-six to ninety days between periods. In contrast, about 10 percent will experience an abrupt end to their periods without warning. Nearly twice that number report more bleeding than usual. This may reflect a problem with the lining of the uterus, however, and should be evaluated by a physician.
It’s important to understand that menopause is not a disease. It is a universal event in the human female (assuming she lives to the appropriate age), and there is no getting around it, for good reasons: Given the physical and physiological rigors of childbirth and the length of time required to raise a newborn to near-adulthood, it would be unwise for a woman to become pregnant after she is well into her fifties. While menopause is unavoidable, its impact on individual women varies greatly. It may occur without notice, or it may produce disruptive symptoms. It may generate little in the way of long-term consequences, or its ultimate effect on quality of life may be profound.
The vast majority of women experience menopause between the ages of forty-five to fifty-five, with the average of being fifty-one. However, some women enter this stage of life before age forty and some as late as sixty. There doesn’t seem to be any relationship between the age at which a woman begins her periods and the timing of menopause. Nor does the age of onset appear to be affected by race, marital status, or geography. Smokers, however, typically experience menopause nearly two years earlier than nonsmokers. And women who have had ovaries removed surgically during their reproductive years have, by definition, an abrupt menopause (referred to as surgical menopause). Many women make this important transition with little or no turbulence. Most have one or more symptoms, including hot flashes, night sweats, skin and hair changes, sudden irritability, tingling sensations, sleep disturbances, vaginal dryness, and a decline in sexual desire. And whether or not you experience these acute symptoms, you will need to think about, plan for, and deal with long-term issues: maintaining your overall health, screening for unsuspected diseases, preserving the bones, and making decisions about hormone replacement therapy (HRT). There are some equally important concerns—personal, emotional, vocational, and spiritual issues—that are affected by menopause.
What happens during menopause?
To fully appreciate (if that’s the right word) what happens during menopause, make sure you are clear on what happens during a woman’s normal reproductive cycle.
At puberty, a woman’s ovaries contain a total of about three hundred thousand eggs, and that over the course of her reproductive years she will release between three hundred and five hundred of them, usually one a time on a monthly basis. Most of the rest gradually disappear over that thirty-to forty-year period, until about ten thousand are left at the time of menopause. In addition, follicles become less sensitive over time to the follicle-stimulating hormone (FSH) that is released by the pituitary. Afetr menopause, follicles produce some estrogen, but eventually none complete the process of ovulation. As a result, there is no corpus luteum—the gland that forms from the follicle that has released an egg and that secretes progesterone. Thus the uterus receives some stimulation, but its lining in the endometrium doesn’t progress through its usual maturation process because of decreased availability of progesterone. Menstrual bleeding may thus become erratic. Furthermore, if the endometrium becomes overly stimulated, the thicker lining cannot be sustained and bleeding may be much heavier.
As the follicles become unresponsive to FSH, estrogen and progesterone levels decline but don completely disappear. A low level of hormones continues to exit the ovaries even after the monthly cycles end. Furthermore, some estrogen is created in the adrenal glands and in fatty tissue all over the body. In fact, women with an ample supply of fat may generate enough estrogen to minimize the symptoms that thinner women typically experience when their estrogen levels fall. This is no great benefit, however, because of the many other drawbacks of obesity—one of which, ironically, is increased risk of cancer of the uterus, arising from the increased stimulation of the endometrium by the higher estrogen levels from fat.
Meanwhile, up in the brain, the hypothalamus and the pituitary gland detect lower levels of estrogen and progesterone, and they try to “correct” the situation. In what would appear to be a futile of effort to get the ovaries’ attention, the hypothalamus secretes high levels of gonadotropin-releasing hormone (GnRH) and the pituitary in turn produces high levels of FSH and LH, but to no avail. Indeed, measuring FSH in the bloodstream serves as a useful confirmation that menopause has occurred. Interestingly, the hypothalamus and pituitary never give up; even the most aged women will be found to have very high FSH levels (which is not harmful).
What happens when the estrogen levels drop?
Several changes in the peri-and postmenopausal woman can be attributed to the decline of this important hormone.
Irregular menses. One of the most important signals that the perimenopausal years have arrived I the onset of irregular menstrual cycles, which may vary considerably depending on the amount of estrogen produced by the ovaries and whether or not an egg was produced that month. As a result, there’s no surefire way to tell from the flow pattern whether or not menopause is imminent. For example, a low output of estrogen causes little stimulation for the lining of the uterus to grow, so the menstrual flow may be scant. On the other hand, if ovulation doesn’t occur, the progesterone “ripening” of the uterus won’t either. This may lead to a steady buildup of endometrial lining in the uterus, which can slough off in bits and pieces (producing spotting) or be released in avertable flood of tissue all at one.
In general, a shift toward heavier menstrual flows—whether prolonged in length or very heavy for the usual number of days or both longer and heavier—deserves some attention. While it may reflect a perimenopausal change, it might also be caused by hyperplasia, a worrisome buildup of the uterine lining that might progress to cancer. Even worse, the bleeding could be caused by an overt cancer of the tissue. Fibroids, which are benign muscular growths in the uterus, can also cause heavy bleeding. Less common, but no less important, are assorted problems such as clotting disorders or thyroid disease. In addition, the ongoing blood loss can outstrip the body’s capacity to replace red blood cells, depleting iron stores and leading to iron-deficiency anemia—which, fortunately, is readily correctable.
If you notice that your menstrual flow is getting longer and/or heavier, for two or three cycles keep track of the number of days you bleed, how heavy the flow appears to be (gauged by the number of tampons or pads you need to use to stay ahead of it), and how many days elapse between cycles. Then review the situation with your primary-care physician or gynecologist. When all is said and done, you may need an ultrasound, an endometrial biopsy, or other diagnostic procedures such as dilatation and curettage (D and C) to make sure nothing serious is happening.
What if you skip one or more periods? This is a common pattern for permenopausal women, with the time between cycles increasing until they finally stop altogether. The most significant alternative explanation to rule out, believe it or not, is pregnancy. As long as eggs are traveling down the fallopian tubes and sperm are there to meet them, a pregnancy can begin. If there’s any such possibility, don’t hesitate to bring it up with your doctor, who may not be thinking along these lines.
Hot flashes. These occur in at least 75 percent of menopausal women. They produce a sensation of heat rising from the chest toward the face and arms, accompanied by flushing of the skin, and less often by an increased heart rate and overt sweating. Hot flashes may occur once in a while or several times a day and last anywhere from a few minutes to half an hour.
Hot flashes appear to be associated with changes in estrogen levels, which in turn trigger an overzealous response from the hypothalamus. The hypothalamus also regulates body temperature and other primal functions, partly through changes in blood-vessel diameter, and during menopause it seems to send an overabundance of messages to the circulatory system in response to the fluctuation of estrogen. Fortunately, the hypothalamus eventually adjusts to the change in the hormonal level and calms down, although the process may take three to five years or even longer. For those who take supplemental estrogen, disruptive flashes and flushes usually come to an end relatively quickly.
Vaginal atrophy. The vagina is extremely sensitive to estrogen stimulation and without it the vagina undergoes a number of changes. The mucous membranes that line it become thinner, and its secretions become less abundant and less acidic. The vagina also becomes shorter and narrower. Irritation, itching, and burning may result, a condition known as atrophic vaginitis. These changes may make sexual intercourse more uncomfortable.
Urinary tract problems. The cells that line the bladder and urethra (the short tube connecting the bladder to the outside world) and the muscular layers of these structures become thinner after estrogen levels decline. This may lead to difficulty controlling the release of urine (incontinence), a sensation of needing to void more often (known as frequency), and a burning with the passage of urine (called dysuria). These changes also reduce the normal defenses against bacteria, sometimes causing repeated bladder infections.
Furthermore, loss of muscle tone in the pelvis may lead to stress incontinence, an annoying loss of urine with anything that causes pressure on the abdomen (such as coughing, sneezing, sneezing, or laughing). Stress incontinence is less a hormonal problem than a mechanical one, and it may be improved by a type of exercise that strengthens the “hammock” of muscles (called pubococcygeals) that support the pelvis organs and vaginal tissue. You may have been taught this (known as am kegel exercise) during pregnancy. The next time you urinate, try to stop the flow of urine before the stream ends. Hold it for a count of three, then let go. This tightening of muscles constitutes a kegel exercise, and to strengthen the pelvic floor you need to repeat this process several dozen times per day. Fortunately, you don’t have to pass urine every time. Simply tighten and relax these muscles five or ten times when you stop at a red light, or during a commercial break on the radio or TV. If conservative measures don’t correct the disruptive symptoms of stress incontinence, surgery may be an appropriate option.
Skin changes. Both layers of skin—the epidermis and dermis—are sensitive to estrogen support. At the surface, estrogen promotes lubrication and water retention. In the deeper dermis, estrogen stimulates production of collagen, a protein that maintains thickness and elasticity of skin. As a result, declining estrogen levels accelerate the thinning, drying, and wrinkling of the skin. But so do sun exposure and cigarette smoking. With or without depletion of the ozone layer, ultraviolet (UV) light not only destroys elasticity and promotes wrinkling, but it also provokes anarchy at the cellular level, leading to various forms of skin cancer. It is important to take appropriate measures to protect your skin from the sun, as well as to avoid deliberate exposures to UV rays, whether from the sun or in a tanning booth.
Formication. That’s formication with an M. Derived from the Latin word for ant (formica), it is a sensation that insects are crawling on the skin, experienced at least once by 15 to 20 percent of postmenopausal women. Oddly enough, it tends to occur one or two years after the last menstrual cycle. This condition may be related to sudden changes in small blood vessels.
Night sweats and disturbed sleep. Night sweats relates to estrogen withdrawal are similar to hot flashes but with the added attraction of soaking nightgowns and sheets. Obviously, such an even isn’t conductive to uninterrupted sleep. In addition, some women have difficulty falling asleep or staying asleep, even without the nocturnal soak.
Unfortunately, you can’t automatically assume that these events are caused b estrogen changes. Night sweats on their own may also be caused by infectious or more serious illnesses, including certain malignancies. If these are occurring in the midst of hot flashes and other menopausal events and are relived decisively by estrogen, then the diagnosis is straightforward. But if you have any doubt, talk to your doctor.
Similarly, sleep disturbances may be caused by a variety of problems, especially depression. Again, if a trial of supplemental estrogen brings on a dramatic improvement, the cause is probably hormonal.
Emotional disturbances. There is no doubt that many women experience irritability, mood swings, anxiety, and overt depression during the years surrounding menopause. There has also been no shortage of controversy surrounding the relationship between hormone fluctuations and these emptions. Medical research has not established a consistent link between them nor has it uncovered evidence that hormone therapy routinely solves the problem. Some women have found, however, that supplemental estrogen seems to help calm emotional storms. For many more, however, there are a host of other factors that may need to be addressed: changes in overall health, losses of friends and family members, conflict at home, and imbalance in chemical messengers in the brain (called neurotransmitters) that may play a pivotal role in many cases of depression. It is very important that mood problems during this period of life not be ignored or trivialized and that they are addressed using any and all appropriate investigations and treatments.
This list of symptoms experienced by many women during menopause and postmenopausal years might sound discouraging. The good news is that, while some of the structural changes (such as thinning of the vagina) are essentially universal; many women sail past menopause as if nothing much has happened. And others who are having a lot of problems can get some impressive relief with lifestyle adjustments and medical treatment.
Like so many other physical characteristics, much of the response to the events of menopause is determined by genetics. Some women have a gradual decline in estrogen, for example, which tends to generate fewer symptoms than an abrupt drop or wild fluctuations in hormone levels. Other make enough estrogen away from the ovaries that the symptoms they experience are limited. Also, the hypothalamus and other estrogen-responsive structures may vary in their sensitivity to hormone levels. On the other hand, the quality of prudent self-care can make a major difference as well. Someone who is in poor condition to begin with—whether physically, emotionally, or spiritually—may find any added hormonal hassles of menopause to be intolerable.