What Happens in the Body During Menopause?

Menopause is more than the end of your periods. It is a natural change in your hormones that can affect many parts of the body — including the brain, bones and heart.¹ These changes begin quietly, often years before you notice any symptoms.²

Which Hormones Change During Menopause, and Why?

Menopause happens as the ovaries age.² The ovaries, the brain and a small gland in the brain (the pituitary) normally work together to control your monthly cycle. As the ovaries slow down, this whole team is affected.²

Your ovaries hold a set number of eggs, and this supply only falls over your lifetime.^2,3 There are around a million at birth, about 250,000 by puberty, and fewer than 1,000 by menopause.^1,2 From your mid-thirties, the supply drops faster and the ovaries start to work differently.²

The first changes are the body trying to keep things going. As the egg supply shrinks, the brain sends out more of a hormone called FSH to push the ovaries along — so FSH rises even while oestrogen is still fairly steady.^2,4 A blood test for FSH (or a related marker called AMH) can be an early sign that the ovaries are winding down.^1,2

Later, oestrogen levels swing about and then drop, and progesterone falls too as egg release becomes less regular.^2,4 By the time periods stop for good, the ovaries have largely stopped making oestrogen.²

How Does the Changing Hormonal Environment Affect the Body?

Oestrogen acts on tissues all over the body, so when it changes you can feel the effects in many places at once.⁵

In the brain, these changes affect temperature, mood, sleep and thinking.^3,6 The brain’s built-in thermostat becomes more sensitive, so even a small rise in body temperature can trigger the body to cool itself down quickly — causing the flushing and sweating of a hot flash.⁶ Night sweats are the same thing happening while you sleep.⁶

After menopause the risk to the heart goes up, as falling oestrogen is linked to changes in cholesterol, blood vessels and inflammation.^5,7

Bones are affected too. Oestrogen helps slow down the cells that break down old bone.¹ When oestrogen falls, these cells become more active, bone is lost faster, and bones can weaken fairly quickly.^1,8

The tissues of the vagina and bladder are very sensitive to oestrogen. As it falls they become thinner, less stretchy and drier, which can cause vaginal dryness, itching or burning, discomfort during sex, and a need to pass urine more often or more urgently.^1,3 Unlike hot flashes, these changes tend to build up over time rather than settle on their own.⁴

What Happens to the Menstrual Cycle as Menopause Approaches?

Your periods don’t just stop overnight — they change over several years first.⁵ This run-up is called perimenopause, and it brings unpredictable changes in egg release and in your bleeding pattern.^4,5

Often the timing changes first, so periods may come closer together at the start.^1,2,4 Over time they become irregular — some shorter, some longer, and some months skipped altogether.⁴ An egg isn’t always released, which makes bleeding less predictable.^2,4

During this time oestrogen doesn’t fall in a smooth line — it goes up and down, sometimes higher than usual before dropping away.^2,4 That is why symptoms can change from week to week.² Menopause is only confirmed looking back, once you have gone 12 months in a row with no period.^1,3

Does the Body Produce Any Oestrogen After Menopause?

Yes, but only a little. After menopause the ovaries mostly stop making oestrogen, but the body still makes a small amount of a weaker form by converting other hormones in fat tissue.^2,7,9 Women with more body fat tend to make a bit more this way.^5,9 However, it isn’t enough to protect the bones, heart and other tissues from the drop in oestrogen.⁷

How Does a Woman Feel When the Hormonal Environment Changes?

Symptoms come from these hormone changes affecting the body and brain.¹⁰ They vary a lot — some women barely notice them, while for others they really affect daily life.^3,7

The most common symptoms are hot flashes and night sweats, which affect most women.^1,4 They come from the changes in the brain’s thermostat described above.⁶ They can be mild and occasional, or happen many times a day and badly disturb sleep.^1,6

Poor sleep is common — partly from night sweats, and partly because these hormones affect sleep itself.^1,6,8 Mood changes such as irritability, low mood and anxiety are also common, especially in perimenopause when hormones swing the most.^1,10 Oestrogen affects brain chemicals linked to mood, which may help explain this, though it isn’t fully understood.¹⁰

Many women also notice trouble concentrating, forgetfulness or a feeling of “brain fog”, especially in perimenopause.^10,11 Physical changes can include vaginal dryness, bladder symptoms, achy joints, and changes in skin and hair.^1,3,7 Sex drive may change too, both from the hormones and from coping with other symptoms.^1,3,11

The link between hormones and symptoms is complex: the same changes can feel very different from one woman to the next, depending on her genes, general health, lifestyle and life circumstances.^1,6,10

What You Can Do

• If you are noticing changes — in your periods, your mood, your sleep, or your body — that you think may be related to menopause, it is worth speaking with your doctor or primary care provider.³
• Keep track of your symptoms, including when they occur and how they affect your daily life.
• Understand that menopause is a gradual process, not a single event — and that it involves several hormone changes, not just oestrogen.^2,5,6
• Be aware that hot flashes and night sweats, mood changes, poor sleep, and vaginal and bladder symptoms all come from the same underlying hormone changes.^1,7
• Ask about bone health — bone is lost fastest in the first few years after menopause, so knowing early helps you act early.^1,8
• Always speak with a qualified healthcare professional before making any decisions about treatment or management.

Conclusion

Menopause is a normal stage of life, when periods stop and hormone levels fall.^1,2 Because these hormones act all over the body, the effects can reach the brain, bones, heart and more.^3,5 Understanding what is happening makes it easier to talk to your doctor about managing your symptoms. It can be a tough time, but there are real ways to feel better.⁴

FAQ

1. How long does perimenopause usually last?

Perimenopause can last anywhere from about two to ten years, and it’s different for everyone.^3,5 It’s the run-up to menopause, when egg release and your periods become unpredictable, and it can start before your periods turn irregular.^4,5 How long it lasts depends on things like your genes and lifestyle.^5,6

2. Why do my joints ache during menopause?

Achy, stiff joints are a common menopause complaint.^7,12 This may be linked to oestrogen’s role in calming inflammation, though it isn’t fully understood.¹² These aches are often blamed on age alone, but they may ease or settle as you move through the transition.¹²

3. Does menopause affect the heart?

Yes — the hormone changes of menopause are linked to changes in cholesterol, blood vessels and inflammation, which can raise the risk to your heart.^5,7 This is part of why heart risk goes up after menopause, although many things besides hormones play a part.⁷

4. What causes vaginal dryness after menopause?

The tissues of the vagina and bladder are very sensitive to oestrogen. As oestrogen falls they become thinner, less stretchy and drier — a common part of menopause.^1,11 This can cause vaginal dryness, discomfort during sex and bladder symptoms.^1,4,11 Unlike hot flashes, it tends to build up over time rather than settle on its own.⁴ There are effective treatments, so it’s worth talking to a healthcare professional.¹¹

5. Can menopause affect memory and concentration?

Yes — trouble with memory, concentration and “brain fog” is commonly reported during menopause. It’s most noticeable in perimenopause, when hormones swing the most. Poor sleep can make it noticeably worse.^10,11

This article was written with the assistance of generative AI technology and reviewed for accuracy.