A woman enters menopause when she has not experienced a menstrual period for more than a year. The perimenopause time occurs when there is a change in menstrual flow and a lengthening of the time between periods. Often, a woman will have a longer cycle length or skip cycles altogether during perimenopause.
The perimenopausal transition begins, on average, at age 47 years and usually lasts from two to five years. The average age of menopause itself is 51 years. Ninety percent of women will be menopausal by 55 years and about 1% of women will experience menopause by age 40.
Surprisingly, we don't know exactly what factors affect the timing of menopause (other than some research suggesting that smokers start menopause earlier than nonsmokers). We know that menopause is affected by a decrease in the hormone estrogen, but we don't know precisely which changes in a woman's body chemistry cause the specific symptoms that accompany menopause. Given that the perimenopausal time lasts for several years and that a woman will be ovulating erratically, there is still a risk of unintended pregnancy during this time. Women should consult with their gynecologist to choose the most effective and desirable method of birth control.
The description of menopausal symptoms passed on from generation to generation of women is varied. The concerns range from "I can't sleep" to "I've been really forgetful and tired" to "I'm really moody." Yet, scientific studies have not confirmed that there is actually a higher rate of many of these symptoms (moodiness, difficulty concentrating, insomnia) associated with the onset of menopause. Many of the symptoms discussed are not unique to menopause. Some physicians suggest that menopause simply worsens symptoms that were already present. For instance, a woman may already have some problems sleeping prior to menopause. Perhaps because the symptoms are mild, they do not significantly impact her daily life. Then, menopause begins and insomnia worsens because of hot flashes. Menopause did not actually "cause" the symptoms, but the two become linked in a woman's mind, because of the timing. There are a few symptoms, however, that are unequivocally associated with the onset of menopause: urogenital symptoms and hot flashes.
Urogenital symptoms involve the urinary tract (i.e. urethra and bladder) or genital tract (i.e. vagina and cervix) and occur because of decreased estrogen levels. This decrease in estrogen results in the atrophy or shrinking of the urogenital tissues. Consequently, there is thinning and shortening of the vagina, which often results in irritation of the urethra (the tube which connects the bladder to the outside of the body) and painful sexual intercourse. Women may also experience an increase in urinary tract infections or urinary incontinence (loss of bladder control).
Hot flashes or hot flushes are the most common menopausal symptom, occurring in up to 80% of women. They may disrupt sleep and last for years. By definition, a flush is associated with a feeling of warmth and occurs spontaneously (e.g., in absence of a hot environment, exercising, etc.). With a hot flash a women might also feel anxious, sweat excessively, or experience a racing heart. Hot flashes likely result from a combination of factors including: a vasodilation response (a relaxation of blood vessels which allows more blood flow to skin), decreased estrogen levels, and changes in norepinephrine and serotonin levels (neurotransmitters or chemical messengers in the brain and nervous system).
The treatment of menopause is varied and includes lifestyle and dietary changes, herbs, and traditional medications. While estrogen has been the most common and popular treatment across time, a 2000 study by the National Institute of Health found that many menopausal women seek symptom relief from complementary therapies. More specifically, 21% of women relied exclusively on complementary therapies; 25% of women used a combination of complementary and traditional therapies; and 19% of women used hormone replacement therapy exclusively.