Understanding the Different Types of Menopause
Menopause is a biological process that marks the end of a woman’s reproductive years – but the path to and through it can vary significantly from person to person. This guide aims to clarify the various types of menopause and related conditions, providing you with a comprehensive understanding of this important life transition.
The language around menopause, especially when it’s not naturally occurring, is full of overlapping, inconsistent, and even misleading terms. No wonder many people feel lost, mislabelled, or left out entirely. This section aims to clarify the main categories, while also acknowledging the confusion built into the current medical definitions.
Natural (Spontaneous) Menopause
Natural or spontaneous menopause occurs gradually, typically between ages 45 and 55, with the average onset around 51 years in New Zealand. Often referred to as “the change” or, in medical terms, the “climacteric,” this process is divided into three stages:
- Perimenopause: The transitional period leading up to menopause, usually beginning in a woman’s 40s, but can be earlier. Symptoms include irregular periods, hot flushes, mood swings, and changes in sleep patterns. This phase can last up to 10 years before menopause.
- Menopause: Officially diagnosed when a woman has gone 12 consecutive months without a menstrual period. Technically, menopause is a single day that marks the end of menstruation.
- Postmenopause: The years following menopause. Symptoms often diminish but may persist. Long-term health risks such as osteoporosis and heart disease become more significant concerns.
| Fun Fact: The term “menopause” comes from the Greek words menos (month) and pausis (cessation), literally meaning the “pause of menstruation.” |
Early Menopause
Early menopause refers to menopause occurring before age 45. It can be natural or induced by medical interventions.
Premature Menopause
Premature menopause occurs at or before age 40 and can be triggered by:
- Medical procedures or treatments
- Genetic factors
- Autoimmune disorders
Primary (or Premature) Ovarian Insufficiency (POI)
Primary (or Premature) Ovarian Insufficiency (POI) – previously known as Primary Ovarian Failure (POF) – is a condition where the ovaries lose normal function before age 40. It affects about 1% of women under 40 and 0.1% of women under 30. POI leads to irregular or absent periods, infertility, and reduced hormone production. It’s a clinical diagnosis made when a woman under 40 has:
- Signs of reduced or absent ovarian function
- Irregular or absent periods (amenorrhea) for at least 4 months
- Elevated follicle-stimulating hormone (FSH) levels on two separate tests
POI can have a range of causes, including genetic and autoimmune conditions, or medical treatments. Hormone replacement therapy (HRT) is commonly recommended to manage symptoms and help protect bone and cardiovascular health.
| Important distinction: Unlike premature menopause, POI is not always permanent. Women with POI may still occasionally ovulate, menstruate, or even become pregnant. Because of this, they are not considered to be in menopause – although they may experience similar symptoms and long-term health risks (such as osteoporosis or cardiovascular concerns). |
POI vs Premature or Induced Menopause – Why It’s So Confusing
POI is a medical diagnosis used to describe reduced or absent ovarian function before age 40. However, in clinical literature and research, the term is often used as an umbrella that includes not only spontaneous POI (from autoimmune, genetic, or unknown causes), but also menopause caused by medical treatments or surgery.
This can be frustrating – particularly for those who’ve had a bilateral oophorectomy (surgical removal of both ovaries) – as they no longer have ovaries at all. In such cases, the idea of “insufficiency” isn’t just technically inaccurate; it can feel dismissive of the reality that their ovarian function is not diminished – it is entirely absent and irreversible.
| Note: Although POI and surgical menopause may result in similar symptoms, they are fundamentally different experiences, especially when it comes to fertility, hormone patterns, and emotional impact. It’s important that these differences are recognised and respected in both medical care and peer support. |
For more information on POI, visit Early Menopause New Zealand.
Induced Menopause (or Medically-Induced Menopause)
For many women, menopause is triggered by medical treatment, which is referred to as induced menopause (or medically-induced menopause), and it can result from surgery, chemotherapy, radiotherapy, or certain medications. Even when the ovaries remain in place, they may stop functioning properly after treatment. The effect may be temporary or permanent, depending on the type and intensity of the intervention.
Induced menopause can also be referred to as iatrogenic menopause. The term “iatrogenic” comes from the Greek word iatros, meaning “doctor,” so it translates to “doctor-caused” menopause.
To make matters more confusing, as mentioned earlier, induced menopause is often grouped under primary ovarian insufficiency (POI) in medical literature. Induced menopause can be further categorised into:
Surgical Menopause (or Surgically-Induced Menopause)
This occurs when both ovaries are surgically removed (a bilateral oophorectomy). It is a major focus of this website, as it represents a subcategory of early menopause that remains under-researched, under-recognised, and under-supported – despite its significant and distinct challenges. Surgical menopause is considered premature if it occurs before age 40. Because the ovaries are removed, women do not go through the gradual transition of perimenopause, but instead experience an abrupt and often intense onset of menopausal symptoms.
Chemical Menopause (or Chemically-Induced Menopause)
This form of menopause is triggered by certain medications or medical treatments – such as chemotherapy, radiation therapy, tamoxifen, or gonadotropin-releasing hormone (GnRH) analogue injections. The resulting ovarian shutdown may be temporary or permanent, depending on the type of treatment, the dosage, and how the individual responds.
Timeline of Menopause
Understanding the different types of menopause is essential for managing this phase of life effectively. Each type presents unique challenges and requires tailored care. Our focus on surgical menopause reflects its specific difficulties, which are often overlooked. By providing clear definitions and guidance, we aim to support women through their menopausal journey, no matter which path they are on.
References
Australasian Menopause Society, What is Menopause? (May 2022).
National Cancer Institute, Fertility Issues in Girls and Women with Cancer (May 9, 2024).
Chon SJ, Umair Z, Yoon MS. Premature Ovarian Insufficiency: Past, Present, and Future. Front Cell Dev Biol. (May 2021).
Australasian Menopause Society, Early Menopause – Chemotherapy and Radiation Therapy (Oct 2020).
[Updated: 18 July 2025]
Surgical Menopause New Zealand Trust 