Menopause is the stage of reproductive ageing at which menstrual periods stop permanently, marking the end of a woman's reproductive years. It is a physiological transition caused by falling ovarian hormone production, and it is generally regarded as a normal part of ageing rather than a disease. Its effects extend beyond the cessation of periods to the bones, cardiovascular system, urogenital tract, sleep and mood, which is why it is studied in medicine and public health as well as in physiology.
Definition and diagnosis
Menopause can only be identified in hindsight. It is defined as having no periods for 12 months in a row, provided this change is not caused by another medical condition. The stage before this point, when cycles become irregular, is called perimenopause.
Diagnosis is usually clinical. In individuals with a characteristic history, such as the typical age of menopause with vasomotor symptoms and amenorrhea, a diagnosis of perimenopause or menopause can be made clinically. Laboratory testing is generally reserved for cases where the stage is unusually early or where other conditions must be excluded: diagnostic tests are reserved for individuals with premature menopause (i.e., before the age of 40 years) or if the clinical history requires the exclusion of alternative diagnoses.
Timing and types
Across populations the typical age is about 51, but there is considerable spread. Most women reach menopause between ages 45 and 55, with the average age being about 51. Smoking is associated with earlier onset: in the United States the average age is 51 for non-smokers and 49 for smokers.
Terminology distinguishes several categories:
- Early menopause occurs between the ages of 40 and 45.
- Premature menopause occurs before age 40. About 1% of women experience menopause before age 40.
- Induced menopause follows surgical removal of the ovaries or treatments such as chemotherapy. Induced menopause leads to a swift decline in hormones, with menopause occurring earlier and more rapidly compared to physiological menopause.
Physiology
Menopause reflects the exhaustion of the ovarian reserve. Menopause is caused by the decline in the number and function of ovarian follicles, which are the structures in the ovaries that contain eggs. As this happens, the ovaries eventually stop releasing eggs and produce less estrogen and progesterone.
The hormonal change is not a simple linear fall. As women approach mid-life, estrogen levels start to fluctuate and then drop. One review proposes that the symptoms of this period arise partly from mismatches between falling hormone levels and receptor availability, a hypothesis that remains under study rather than established consensus: this results in periods of hormone-receptor imbalances, exacerbating the effects of lower serum estrogen and is considered the primarily endocrinal source of menopause symptoms.
Symptoms
The most characteristic symptom is vasomotor instability. Hypothalamically mediated vasomotor instability leading to hot flashes (hot flushes), sweating, and palpitations is the most common presentation of menopause. These symptoms occur in more than 60% of postmenopausal women. Sleep disturbance, mood change and sexual symptoms are also common, and the severity varies widely. In approximately 25% of patients, menopausal symptoms are debilitating. Some women have few or no symptoms: although some women go through the menopausal transition without symptoms, many women have hot flashes or genital tract symptoms, such as vulvar or vaginal dryness, painful intercourse, and urinary problems.
The genitourinary changes are grouped as genitourinary syndrome of menopause, which includes vulvovaginal atrophy, vaginal dryness, urinary tract infections, and more.
Longer-term consequences are a major concern for public health. Women's advantage over men in terms of cardiovascular disease gradually disappears with the significant decline in oestrogen levels after menopause. Loss of bone density at menopause is a significant contributor to higher rates of osteoporosis and fractures. Pelvic support may also weaken: menopause can also result in the weakening of the pelvic support structures, increasing the risk of pelvic organ prolapse.
Management
Management is tailored to symptom severity and to individual risk. Nonpharmacological interventions are recommended for mild symptoms. Pharmacological therapy is used for moderate to severe symptoms that impair quality of life and for patients with premature, early, or induced menopause who are at increased risk for complications of menopause.
Among drugs, menopausal hormone therapy remains the most effective option for hot flashes. Menopausal hormone therapy (HT) involves the administration of estrogen, with or without a progestogen, to alleviate the symptoms of menopause. Women with a uterus who are using estrogen should also take a progestogen to reduce the risk of endometrial cancer. Treatments are available in several forms, and it can be given in pills, skin patches, rings, implants, gels, or creams. Low-dose local vaginal estrogen is used for genital symptoms and is considered separate from systemic therapy, as it does not carry the same risks as systemic treatment.
Non-hormonal options exist. Although estrogen is the most effective treatment for hot flashes, nonhormonal alternatives such as low-dose paroxetine, venlafaxine, and gabapentin are effective alternatives.
Hormone therapy: history and debate
Attitudes toward hormone therapy have shifted substantially. Before 2002, HT was generally accepted as appropriate and safe for treatment of menopausal symptoms, as well as for chronic disease prevention including cardiovascular disease (CVD) prevention. The Women's Health Initiative (WHI) trials changed this. The combined estrogen and progesterone trial was terminated early, in 2002, when results showed an increased risk in heart disease, stroke, blood clotting disorders and breast cancer, as well as cognitive decline and dementia. The trial of estrogen alone also raised safety concerns, though both types of therapy reduced the risk of bone fractures. After these findings were reported, menopausal hormone therapy prescriptions dropped sharply in the U.S. and worldwide.
Later reanalysis introduced the age and timing of initiation as key variables. Sub-analysis of the WHI results by age group showed that the elevated risks identified for coronary heart disease (CHD) applied mainly to women who started HT after age 60 or a decade past menopause. The resulting "timing hypothesis" proposes that HRT initiated within 10 years of menopause onset or before age 60 may confer cardiovascular benefit, whereas later initiation may increase cardiovascular risk. Professional guidance now reflects this distinction. The North American Menopause Society position statement from 2022 notes that the risk/benefit ratio is favorable when treating vasomotor symptoms and prevention of bone loss in women under 60 or who are within 10 years of menopause onset and have no contraindications.
The debate has not been fully resolved. This is an area of continued debate among experts, including those at a recent US Food and Drug Administration (FDA) panel on menopausal hormone therapy. Some researchers remain cautious about starting treatment in later life, and it is generally recommended that decisions be made individually, weighing benefits and risks with a clinician.
Demographic context
Because women live longer, a growing share of life is spent after menopause. In 2021, women aged 50 and over accounted for 26% of all women and girls globally. Globally, a woman aged 60 years in 2019 could expect to live on average another 21 years. This makes the long-term health effects of menopause a significant issue for life expectancy-related planning, epidemiology and health services.
Men and the term "male menopause"
The word is sometimes applied to men. Andropause, or male menopause, is a term that describes decreasing testosterone levels in men. The comparison is contested: healthcare providers often debate calling this slow decline in testosterone "menopause" since it's not as drastic of a hormone shift and doesn't carry the same intensity of side effects.
Open questions
Research continues on the timing and duration of hormone therapy and on the relationship between menopause and later disease. Future research is needed to clarify optimal timing and duration of hormone therapy, particularly for women with premature menopause, and studies continue to examine links with conditions such as dementia and osteoporosis.
References
- Menopauseyalemedicine.org
- Menopause - Knowledge @ AMBOSSamboss.com
- Menopauseendocrine.org
- Menopause: What is Menopause? Menopause Symptoms, Treatment, Diagnosis - Comprehensive Menopause Careuclahealth.org
- EPIDEMIOLOGIC GEROSCIENCE INNOVATIONS AT THE NEXUS OF REPRODUCTIVE AGING AND WOMEN’S HEALTHncbi.nlm.nih.gov
- Shifts in endocrine homeostasis and preventive hormone replacement therapy: extending the Women’s Health Initiative globallyncbi.nlm.nih.gov
- Menopausal Hormone Therapy: Overview, Symptoms and Effects of Menopause, Forms of Therapyemedicine.medscape.com
- Hormone Therapy and Other Treatments for Symptoms of Menopauseaafp.org
- Menopausewho.int
- Menopausemedlineplus.gov
- Risks, Benefits, and Treatment Modalities of Menopausal Hormone Therapy: Current Conceptsncbi.nlm.nih.gov
- The Women’s Health Initiative has shaped women’s health for over 30 years, but its future is uncertaintheconversation.com
- The impact of hormone replacement therapy on cardiovascular health in postmenopausal women: a narrative reviewncbi.nlm.nih.gov
- Women's Health Initiativeen.wikipedia.org
- New Analysis of Women’s Health Initiative Data Aims to “Clear the Air” Over Menopausal Hormone Therapyjamanetwork.com
- Menopause: What It Is, Age, Stages, Signs & Side Effectsmy.clevelandclinic.org
- After the Women's Health Initiative: Menopausal Women and Hormone Therapyjournalofethics.ama-assn.org
- Association between menopause-related symptoms and muscle mass index among perimenopausal and postmenopausal women and the mediating role of estrogen levelsncbi.nlm.nih.gov
- Menopausal Hormone Therapy, an Ever-Present Topic: A Pilot Survey about Women’s Experience and Medical Doctors’ Approachncbi.nlm.nih.gov
- Hormone Therapy for Menopauseacog.org
- Hormone therapy: Is it right for you? - Menopausemayoclinic.org