Menopause is the permanent end of periods, confirmed after 12 months without menstruation (average age 51). Learn the stages, symptoms like hot flashes, and treatments from lifestyle changes to hormone therapy.
Menopause is the permanent end of menstrual periods, marking the conclusion of female fertility. By definition, menopause is reached when twelve consecutive months have passed without a period, in the absence of any other cause. The average age of onset is around 51 years, with a physiological range between 45 and 55 years.
In my practice I see women who arrive frightened by menopause as if it were a sentence — my first task is to normalize it: this is physiology, not pathology, and today we have very effective tools to manage the symptoms.
The transition does not happen overnight. The journey unfolds in three distinct phases, described by the international STRAW+10 classification:
Perimenopause (or the climacteric) begins with the first irregularities of the menstrual cycle and lasts on average four to eight years. Hormones fluctuate, periods become unpredictable, and the first vasomotor symptoms appear. This is the phase many women find disorienting, precisely because the changes do not follow a linear curve.
Menopause is technically a single point in time — the anniversary of the last menstrual period — but clinically it is diagnosed using the criterion of twelve months of amenorrhea.
Postmenopause begins after that moment and continues for the rest of life. Acute symptoms tend to ease over the first two to three years, while those linked to urogenital atrophy and loss of bone density become progressively more significant.
Menopause can also occur in an iatrogenic way: following a hysterectomy with bilateral oophorectomy, during chemotherapy, with treatments for endometriosis, or in the treatment of breast cancer with anti-estrogens. In these cases the transition is abrupt and the symptoms are often more intense.
What causes menopause?
Women are born with a predetermined number of follicles. From puberty onward, about twenty of these begin a maturation process each month, which is completed by only one of them, the egg that can be fertilized.
As a woman ages, therefore, the number of follicles declines and the granulosa cells in the ovary degenerate and no longer produce estradiol and inhibin.
The decline in estrogen levels disrupts the hypothalamic-pituitary-ovarian axis, reducing endometrial development and leading to irregular menstrual cycles until they cease completely.
Menopause can also be triggered by:
a hysterectomy with bilateral oophorectomy;
treatments for endometriosis, which can induce it;
breast cancer treatment with anti-estrogens;
chemotherapy for other cancers.
How does menopause happen? The physiology
Menopause is the permanent end of menstrual periods, marking the conclusion of female fertility. By definition, menopause is reached when twelve consecutive months have passed without a period, in the absence of any other cause. The average age of onset is around 51 years, with a physiological range between 45 and 55 years.
In my practice I see women who arrive frightened by menopause as if it were a sentence — my first task is to normalize it: this is physiology, not pathology, and today we have very effective tools to manage the symptoms.
The transition does not happen overnight. The journey unfolds in three distinct phases, described by the international STRAW+10 classification:
Perimenopause (or the climacteric) begins with the first irregularities of the menstrual cycle and lasts on average four to eight years. Hormones fluctuate, periods become unpredictable, and the first vasomotor symptoms appear. This is the phase many women find disorienting, precisely because the changes do not follow a linear curve.
Menopause is technically a single point in time — the anniversary of the last menstrual period — but clinically it is diagnosed using the criterion of twelve months of amenorrhea.
Postmenopause begins after that moment and continues for the rest of life. Acute symptoms tend to ease over the first two to three years, while those linked to urogenital atrophy and loss of bone density become progressively more significant.
Menopause can also occur in an iatrogenic way: following a hysterectomy with bilateral oophorectomy, during chemotherapy, with treatments for endometriosis, or in the treatment of breast cancer with anti-estrogens. In these cases the transition is abrupt and the symptoms are often more intense.
What are the effects of the hormonal decline in menopause?
The hormonal decline affects practically every system in the body.
Central nervous system: the hypothalamus loses the stability of its thermoneutral zone — the circuit that regulates body temperature — leading to the onset of hot flashes. KNDy neurons (kisspeptin, neurokinin B, dynorphin) play a central role in this mechanism: neurokinin B directly activates the neurons of the thermoregulatory center.
Skeletal system: the drop in estrogen accelerates bone resorption, increasing the risk of osteoporosis and fractures. Bone loss can reach 2–3% per year in the first years of postmenopause — up to ten times faster than the physiological loss in a man of the same age.
Cardiovascular system: the lipid profile changes for the worse, with a rise in LDL and a fall in HDL, and the endothelium loses its estrogen protection. A woman's cardiovascular risk progressively approaches that of a man.
Urogenital tract: the vaginal mucosa, the urethra and the bladder trigone thin out due to estrogen deficiency, producing what is known as the genitourinary syndrome of menopause — dryness, dyspareunia, urinary urgency. At the histological level, the ovarian cortex becomes thinner and its surface shows invaginations and cysts.
What are the symptoms of menopause?
The symptoms of menopause vary considerably from one woman to another: 25% have no significant symptoms, while a minority experience them in a very severe form. This variability is determined by genetic, metabolic, psychological and cultural factors.
Vasomotor symptoms
About 75% of women in menopause report vasomotor symptoms, which are the most frequent and recognizable complaint. Hot flashes last about 3–4 minutes and are triggered by hot food, alcohol, stress and physical exertion. They are accompanied by night sweats (flashes that occur during sleep, fragmenting rest), palpitations and migraines.
Hot flashes tend to peak in the first years of postmenopause and then gradually decline, although in 10% of women they persist beyond ten years. Anxiety levels and sleep disturbances caused by chronic night sweats in turn produce irritability and a reduction in cognitive function.
Urogenital symptoms
In early postmenopause (the first two to five years) symptoms of urogenital hypoestrogenism emerge: vaginal atrophy with dryness and fragility of the mucosa, dyspareunia (pain during intercourse), reduced sexual desire, and urethral atrophy with incontinence, urinary urgency and difficulty urinating. In late postmenopause, urogenital atrophy becomes progressive and is one of the main challenges of long-term management.
Psychological symptoms
Irritability, anger, loss of concentration and a sense of cognitive fog are common during perimenopause. Many women report a loss of self-esteem and mood swings that do not follow a predictable pattern. These symptoms have a direct biological basis — hormonal fluctuations act on the serotonergic and noradrenergic systems — and should never be reduced to a simple emotional reaction to change.
How is menopause diagnosed?
The diagnosis of menopause is clinical in women over the age of 45: amenorrhea lasting twelve months in the absence of other causes is sufficient. Routine laboratory tests are not necessary in this context.
Measuring FSH (follicle-stimulating hormone) — which is typically above 30 mIU/mL in established menopause — is useful in women under 45 or when the diagnosis is uncertain (for example, in women taking oral contraceptives). Anti-Müllerian hormone (AMH) reflects the ovarian reserve but is not necessary for the diagnosis of physiological menopause.
If a patient has had her ovaries surgically removed or has undergone chemotherapy, menopause can be diagnosed immediately without waiting for the 12 months of amenorrhea. In these cases the physician may use hormone measurements to confirm it.
How do you reach menopause? The reproductive staging system and FSH levels
In 2011, the STRAW+10 staging system classified the female reproductive cycle into three main phases, each with defined sub-stages:
In the reproductive phase the cycle is regular, with physiological variations in flow and duration. FSH levels between the second and fifth day of the cycle are low.
In the menopausal transition the variability in cycle length becomes increasingly marked. In the early stage the cycles shorten; in the late stage, periods of amenorrhea of 60 days or more appear, and FSH values rise. This phase lasts from one to three years.
In postmenopause, menstruation has ceased. Perimenopause continues until there has been no period for a full year. FSH levels remain elevated and gradually stabilize. In early postmenopause, vasomotor symptoms predominate; in late postmenopause, genitourinary symptoms prevail, including vulvovaginal atrophy, dryness, and lower urinary tract symptoms such as frequency, urgency and nocturia.
Differential diagnosis: other causes of absent periods
In young women with amenorrhea, the first cause to rule out is always pregnancy. Once that has been excluded, the pathological causes include:
Hypothyroidism, a common cause of menstrual irregularity, with symptoms that overlap with menopause (fatigue, weight gain, mood changes).
Hyperprolactinemia, which can cause amenorrhea and galactorrhea.
Premature ovarian insufficiency in women under 40 — a condition distinct from physiological menopause that requires a specific diagnostic and therapeutic pathway.
Polycystic ovary syndrome (PCOS), especially during perimenopause, when menstrual irregularities can overlap.
Primary hypogonadism (a reduction in estrogen due to direct ovarian malfunction or damage) and secondary hypogonadism (where the cause lies in the lack of stimulation from the pituitary gland — the defect is in the control axis of ovarian secretion).
How is menopause treated?
Treatment for menopause aims to improve symptoms and prevent long-term complications.
The treatment of menopause follows a stepwise approach that always starts with lifestyle changes.
Lifestyle
Regular physical exercise — both aerobic and resistance training — is the intervention with the greatest number of documented benefits: it reduces hot flashes by 20–30%, protects the bones, and improves the cardiovascular profile and mood. The Mediterranean diet, with an adequate intake of calcium (1,200 mg per day) and vitamin D (1,500–2,000 IU per day), reducing alcohol and quitting smoking complete the picture of preventive measures. The technique of slow, controlled breathing (paced breathing, six breaths per minute) has been documented to reduce the frequency and intensity of hot flashes.
Hormone therapy for menopause
Hormone therapy consists of using estrogen, or a combination of estrogen and progestogen, to compensate for the hormonal deficiency. The hormones are administered orally, transdermally (patch), vaginally or by injection. It is the most effective treatment for vasomotor symptoms and for the genitourinary syndrome. The risk-benefit profile is favorable in women under 60 or within ten years of menopause, in the absence of contraindications. Fear of hormone therapy is often based on studies from 2002 that have now been superseded by two decades of research.
Among the available options: estrogens, estrogen-progestogen combinations, estrogen-bazedoxifene, progestogen alone, combined oral contraceptives, and selective estrogen receptor modulators (which modulate estrogen action without causing endometrial hyperplasia).
Care must be taken with the use of estrogen unopposed by a progestogen in women who still have a uterus, since it could increase the risk of endometrial hyperplasia and uterine cancer.
Non-hormonal therapy
Medications for vasomotor symptoms and mood: in cases where hormone therapy is contraindicated or not desired, effective alternatives include fezolinetant (an NK3 receptor antagonist, approved by the EMA in 2024, the first non-hormonal drug developed specifically for hot flashes), SSRIs such as low-dose paroxetine, SNRIs such as venlafaxine, and gabapentin. Soy isoflavones and black cohosh (Cimicifuga racemosa) have moderate evidence but a favorable safety profile.
Medications for the prevention of osteoporosis: bisphosphonates (alendronate, zoledronate), denosumab, raloxifene, supplementation with calcium (1,000–1,200 mg/day) and vitamin D (800–2,000 IU/day depending on the baseline level).
Local therapy for the genitourinary syndrome: low-dose topical estrogens (estriol, estradiol), intravaginal dehydroepiandrosterone (prasterone) and oral ospemifene are effective and safe even over the long term.
Cardiovascular health in postmenopause
Annual monitoring of blood pressure, lipid profile and blood glucose becomes a priority in postmenopause. The loss of estrogen protection makes active cardiovascular prevention — exercise, diet, not smoking — essential.
Menopause and mental health
An often-underestimated aspect is the impact of menopause on mental health. The risk of depression increases significantly during perimenopause — not as an emotional reaction to change, but as a direct consequence of hormonal fluctuations on the serotonergic and noradrenergic systems. Women with a history of perinatal or premenstrual depression are particularly vulnerable.
Sleep disturbances caused by chronic night sweats in turn produce anxiety, irritability and reduced cognitive function that can be mistakenly attributed to a primary psychiatric disorder. Treating vasomotor symptoms often improves the psychological picture as well.
I always tell my patients: menopause does not take anything away from you, it changes the rules of the game. And the new rules, once you have learned them, work very well.
Menopause and bone health: prevent before a fracture occurs
Over ten years of untreated postmenopause, a woman can lose 20–30% of her vertebral bone density. The central mechanism is the loss of the inhibitory action of estrogen on osteoclasts: without estrogen, the balance between bone formation and resorption shifts markedly toward resorption, especially in the trabecular bone of the vertebrae and the femoral neck.
Early diagnosis relies on bone densitometry (DEXA), recommended in women with risk factors (smoking, low body weight, family history of fractures, chronic corticosteroid use) or after the age of 65. A T-score between -1 and -2.5 indicates osteopenia; below -2.5 it is defined as osteoporosis.
Weight-bearing physical exercise (walking, running, resistance exercises) stimulates bone formation through mechanical stress. Smoking is an independent risk factor for postmenopausal osteoporosis and must be addressed actively. Hormone replacement therapy is effective in preserving bone density while it is being taken, but the protection ceases when it is stopped.
Frequently asked questions
At what age does menopause start?
The average age is 51, but the physiological range runs from 45 to 55 years. Before the age of 40 it is called premature ovarian insufficiency, a different condition that requires a specific diagnostic and therapeutic pathway.
How do I know if I am in menopause?
If you are over 45 and have not had a period for at least twelve months with no other explanation, you are technically in menopause. During perimenopause the diagnosis is more complex because the cycle is irregular but not yet absent. If in doubt, a hormone measurement (FSH and estradiol) can clarify the situation.
Do you gain weight during menopause?
Body weight tends to increase during menopause, but estrogen deficiency is not the direct cause — it is the metabolic slowdown linked to age and the reduction in muscle mass. The distribution of fat shifts toward a more visceral (abdominal) pattern, independently of any weight gain. Resistance exercise is the most effective tool to counter this change.
Is hormone replacement therapy dangerous?
Hormone therapy has a favorable risk-benefit profile in women under 60 or within ten years of menopause, in the absence of contraindications. Fear of hormone therapy is often based on studies from 2002 that have now been superseded by two decades of research.
Can you get pregnant in perimenopause?
Yes. Until twelve months have passed since the last period, there is a theoretical possibility of ovulating and conceiving. Women in perimenopause who do not want to become pregnant should continue to use contraception.
What are night sweats in menopause?
Night sweats are hot flashes that occur during sleep: they cause a sudden awakening with an intense sensation of heat, profuse sweating and sometimes chills afterward. They fragment sleep and can lead to chronic insomnia with all its consequences for mood and cognitive function. They respond to the same treatments as daytime hot flashes.
Conclusions
Menopause is a phase in a woman's life that marks the end of fertility and menstruation. It generally occurs around the age of 50, but it can vary from person to person.
During menopause, levels of estrogen and progesterone decline, causing changes in the body and in mood.
Several treatment options are available to manage the symptoms of menopause, such as hormone replacement therapy, which can help reduce hot flashes and increase bone density, or dietary supplements such as calcium and vitamin D, to prevent osteoporosis.
References: sources and notes
Dr. Marco De Nardin
Medical Doctor, Specialist in Anesthesiology, Intensive Care and Pain Management
Dr. Marco De Nardin is a physician specializing in Anesthesiology, Intensive Care, and Pain Management. He completed his medical degree and specialty training in Italy, where he continues to practice at his private clinics in Mestre (Venice) and Milan. With extensive clinical experience spanning operating rooms, intensive care units, and pain management clinics, Dr. De Nardin brings a unique perspective that bridges acute-care medicine with chronic disease management. His clinical practice focuses on regional anesthesia, ozone therapy, intravenous infusion therapy, and integrative approaches to pain treatment. He is the founder of Med4Care, a medical information platform delivering evidence-based, physician-reviewed health content. Every article published under his name reflects his commitment to making complex medical topics accessible to patients without compromising scientific rigor.
