For most women, menopause occurs naturally around the age of 49. In the lead up to menopause, the quality and quantity of eggs declines over time. Then the ovaries stop releasing eggs completely.

At this time, the ovaries also stop producing the sex hormones oestrogen and progesterone. This causes menstrual periods to end. When you clock 12 months of no periods, you’re in menopause.

But some women will start menopause quickly after having their ovaries removed in surgery. Others will transition to menopause over a longer timeframe if medical treatments, such as chemotherapy or radiotherapy, damage their ovaries.

So what can you expect from menopause due to surgery or medical treatments?

What treatments can cause menopause?

Surgical menopause occurs when women have their ovaries removed to treat conditions such as ovarian cancer.

Some women with a genetic predisposition to ovarian and breast cancer, such as those like Angelina Jolie who carry the BRCA1 gene, may also have their ovaries removed to stop the production of oestrogen. This reduces the risk of ovarian and breast cancers, which are considered oestrogen-dependent cancers.

Other pelvic surgery can damage the ovaries and trigger menopause, such as removal of ovarian cysts or treatment for endometriosis.

Medical treatments that severely damage or are toxic to the ovaries can also trigger menopause. These include chemotherapy or radiotherapy for cancer, and treatment for rheumatological conditions such as lupus.

Whether you become menopausal after medical treatment will depend on your age, underlying ovarian reserve, as well as the type and dose of chemotherapy or radiotherapy. Younger women generally have greater ovarian stores so can withstand more damage.

When does it happen? How is it diagnosed?

Menopause due to medical treatment may occur earlier than the typical age of natural menopause. When menopause occurs between 40 and 45 years, it’s called early menopause. Around 12% of women will have early menopause.

Before 40, early menopause is called “premature ovarian insufficiency”. This is because for women whose periods spontaneously stop, there’s still a chance of their ovarian function returning. But this is less likely if periods stop due to the effect of medical treatments. And it’s impossible after surgical menopause. Around 4% of women have premature ovarian insufficiency.

The diagnosis of surgical menopause is clear. But making a diagnosis of menopause after medical treatments can be more difficult. The diagnosis is based on four months or more of no or irregular menstrual periods, plus a high follicle-stimulating hormone level, which is determined using a blood test.

What are the symptoms? How do they differ?

Symptoms of oestrogen deficiency, such as hot flushes, usually start quickly after surgical menopause. Other symptoms such as vaginal dryness may develop more slowly. Symptoms of surgical menopause are often more severe than natural menopause.

But every person’s experience is different. And symptoms can vary within and between people. It can also be hard to tell what symptoms are due to menopause and what are due to the underlying health problem or treatment, such as the effects of chemotherapy on cognition.

Low oestrogen from premature ovarian insufficiency can cause vaginal dryness, reduced libido, muscle decline and bone loss, and may also impair brain function. It can also increase risk risk of heart disease and stroke, with a higher risk after surgical menopause than spontaneous premature menopause.

Premature ovarian insufficiency can can also result in poorer mental health and quality of life, and can impact your ability to work.

Women with surgical menopause cannot become pregnant, while women with premature ovarian insufficiency are unlikely to fall pregnant naturally.

How is it treated?

Our previous research has shown women with early menopause and premature ovarian insufficiency often receive poor health care. There is a large variation of quality between health providers.

To assist health-care professionals provide best-practice care, in 2024 we updated the evidence-based guidelines with 145 recommendations to treat early menopause and premature ovarian insufficiency.

Hormone-replacement therapy (HRT), which replaces the missing oestrogen (plus progesterone if you still have your uterus), is the mainstay of treatment for women with premature ovarian insufficiency and early menopause.

Women who have undergone surgical menopause or are experiencing premature ovarian insufficiency can consider HRT for symptom relief and bone protection.

However, HRT cannot be used if you have certain health conditions such as hormone-sensitive breast cancers.

It’s important you talk to you health-care provider about the pros and cons of HRT in your situation.

Other treatment options include:

• vaginal oestrogen, which can be helpful for vaginal dryness
• cognitive behavioural therapy (CBT), which be helpful for managing hot flushes, sleep and mood.

Although Chinese herbal medicine may alleviate menopausal symptoms in some women, overall there isn’t enough scientific evidence that complementary therapies can effectively manage premature ovarian insufficiency.

Health practitioners should talk to patients about the likely symptoms and risks of surgical menopause and premature ovarian insufficiency before starting any treatments that can cause these conditions.

Options to minimise these risks and preserve fertility should also be discussed and may require a referral to a specialist.

Carolyn Ee, Associate Professor, Cancer Survivorship and Primary Care, Caring Futures Institute, Flinders University; Western Sydney University and Amanda Vincent, Adjunct Clinical Associate Professor and Endocrinologist, Monash University

This article is republished from The Conversation under a Creative Commons license. Read the original article.