1. Bone loss
The timing of bone loss is different from what most people assume: it begins 1–2 years BEFORE the last period and continues for a further 3–4 years afterwards.
The fastest loss happens in the three-year window running from one year before to two years after the last period. In that short time an average of 10.6% of bone mass is lost from the lumbar spine and 9.1% from the femoral neck at the hip.
In other words, the loss may already have begun before menopausal symptoms become obvious.
The most common mistake in assessment
Contrary to what is often assumed, the great majority of fractures after the menopause do not occur in people who are at the "osteoporosis" threshold, but one step above it — in people whose bone mass is only mildly reduced (osteopenia).
Bone health should therefore not be judged on the measurement score alone; it needs to be considered together with whole-person risk assessment tools. See the menopause health check page for more detail.
2. Heart and blood vessels
Oestrogen keeps blood vessels flexible and supports the healthy working of the vessel lining. When oestrogen is withdrawn the vascular bed is left unprotected and blood pressure regulation becomes more easily disturbed.
Blood fats change in the same period: total cholesterol, "bad" cholesterol and triglycerides rise, while "good" cholesterol falls. This picture increases arterial stiffness and the risk of cardiovascular disease.
Why does timing matter so much? When hormone therapy is started within the first 10 years of the menopause or before the age of 60, coronary heart disease, heart failure and cardiovascular deaths are reported to be reduced by roughly half. The same treatment started later does not show this benefit. See the hormone therapy page for more detail.
3. The brain and thinking
Oestrogen governs how the brain uses glucose, its main fuel. With the menopause there is a temporary fall of 20–25% in the brain's use of glucose, and the brain shifts to a different fuel arrangement to close the energy gap.
That transition is the explanation for what is called "brain fog": difficulty finding words, trouble concentrating and absent-mindedness. It is not imagined, and it is not an "inevitable part of ageing" — it is a measurable metabolic shift.
After the menopause the brain also has to work harder to reach the same memory performance — it spends more energy for the same task.
An important limit: although protective effects of oestrogen in the brain have been described, guidelines do not recommend starting hormone therapy solely to prevent dementia in women going through a natural menopause. This is an honest distinction that belongs on the page.
4. Muscle mass and where body fat sits
- Muscle loss: a lack of oestrogen weakens the capacity of muscle to renew itself; muscle mass and strength decline.
- Fat moves: the distribution of fat changes permanently — it collects around the abdomen and around the internal organs rather than at the hips.
Fat inside the abdomen drives the risk of metabolic syndrome, insulin resistance and type 2 diabetes. Where the weight sits matters more than the weight itself.
5. The genitourinary system
The tissues of the vagina, vulva, bladder and urinary tract are the areas most sensitive to a lack of oestrogen. These tissues become thinner, lose elasticity, and their acidity is disturbed.
The result is persistent vaginal dryness, burning, stinging on passing urine, pain during intercourse and frequently recurring urinary tract infections. See the genitourinary syndrome page for more detail.
How do the risks change in early menopause?
Losing ovarian function before the age of 40, or reaching the menopause before 45, leaves the body facing a sudden lack of oestrogen during its most productive years. The risks rise markedly here.
- Life expectancy: in women with early menopause who do not use hormone therapy, life expectancy is reported to be shortened. The main reason is rapidly progressing cardiovascular disease.
- Heart and vessels: there is a serious increase in the risk of coronary heart disease, heart failure, rhythm disturbance and stroke. The data show that each year spent without oestrogen independently increases the risk of a cardiovascular event.
- Menopause caused by surgery — removal of both ovaries — takes a faster and more severe course than spontaneous early menopause.
- The brain: in women who have both ovaries removed before the age of 45 in particular, the risk of cognitive decline and dementia rises markedly and at a much earlier age.
- Bone: because protection is withdrawn while young, the fracture threshold is reached far earlier. A bone measurement at the time of diagnosis is therefore needed, and if loss is found it should be monitored every 1–3 years.
The strongest recommendation in the guidelines: all women diagnosed with early menopause or ovarian insufficiency — even if they have no symptoms at all — are advised to take hormone therapy at least until the age of natural menopause (on average 50–51) in order to protect the health of the heart, the bones and the brain.
In this younger group the benefits of hormone therapy are much greater and the risks much lower than in older women.
Frequently Asked Questions
When does bone loss start?
Earlier than most people think: loss begins 1–2 years before the last period and continues for a further 3–4 years. The fastest loss is in the three-year window from one year before to two years after the last period — in that short time an average of 10.6% of bone mass is lost from the lumbar spine and 9.1% from the femoral neck.
My bone scan came back “borderline” — can I relax?
No, and this is the most common mistake in assessment. The great majority of fractures after the menopause occur not at the “osteoporosis” threshold but one step above it, in people whose bone mass is only mildly reduced. Bone health should therefore be judged with whole-person risk assessment tools, not the score alone.
Why does the menopause affect my heart?
Oestrogen keeps blood vessels flexible and supports the healthy working of the vessel lining; when it is withdrawn the vascular bed is left unprotected. In the same period total cholesterol, “bad” cholesterol and triglycerides rise while “good” cholesterol falls. This increases arterial stiffness and the risk of heart disease.
Why does timing matter in hormone therapy?
Because the benefit depends on it. When treatment is started within the first 10 years of the menopause or before the age of 60, coronary heart disease, heart failure and cardiovascular deaths are reported to fall by roughly half. The same treatment started later does not show this benefit.
Is “brain fog” real?
Yes, and it has a measurable basis. Oestrogen governs how the brain uses glucose, its main fuel; with the menopause the brain's use of glucose falls temporarily by 20–25% and the brain shifts to a different fuel arrangement. Difficulty finding words and trouble concentrating follow from that shift — they are not imagined.
Should I take hormone therapy to prevent dementia?
No. Although protective effects of oestrogen in the brain have been described, guidelines do not recommend starting hormone therapy solely to prevent dementia in women going through a natural menopause. The decision to treat is made on other grounds and individually.
My weight is the same but my waist has grown — why?
With the menopause the distribution of fat changes permanently: fat collects around the abdomen and the internal organs rather than at the hips. Muscle mass and strength also decline. Where the weight sits matters more than the weight itself — fat inside the abdomen drives insulin resistance and the risk of type 2 diabetes.
I had an early menopause — is my risk higher?
Yes, markedly. In women with early menopause who do not use hormone therapy, life expectancy is reported to be shortened; the main reason is rapidly progressing cardiovascular disease. Each year spent without oestrogen independently increases cardiovascular risk. Menopause caused by surgery takes a faster and more severe course than spontaneous early menopause.
I have no symptoms — do I still need treatment?
If this is early menopause or ovarian insufficiency, yes. The strongest recommendation in the guidelines is that these women take hormone therapy even if they have no symptoms at all, at least until the age of natural menopause (on average 50–51), to protect heart, bone and brain health. In this age group the benefits are far greater and the risks far lower than in older women.
Sources
- SWAN (Study of Women's Health Across the Nation) — timing and magnitude of bone mineral density loss across the menopausal transition.
- International guideline on premature ovarian insufficiency (POI) — cardiovascular, bone and cognitive risks in early menopause and the recommendation on hormone therapy.
- Sources on the menopause and cardiovascular health — changes in blood lipids and the effect of the timing of treatment on outcome.
- Sources on the menopause and brain metabolism — changes in glucose use, cognitive effects and the place of hormone therapy for that purpose.
The information on this page is based on the national and international guidelines listed above. The page is reviewed whenever those guidelines are updated.
Practice and Contact Details
The information on this page is general. Please speak to your doctor about your own situation.
- DoctorOp. Dr. Murat Alpay — Specialist in Obstetrics and Gynaecology
- AddressOp. Dr. Murat Alpay Practice, Tekelioğlu Cd. No:51 B Kat:2, Filo Apt., 07160 Muratpaşa / Antalya
- Telephone0505 351 77 88
- HoursMonday – Saturday 09:00 – 18:00 · Closed on Sunday