Tag: polyendocrine metabolic ovarian syndrome

If you’ve recently heard the term PMOS and wondered what it means, or if you’ve had a PCOS diagnosis for years and want to understand what’s changed, this is your complete guide. PMOS stands for polyendocrine metabolic ovarian syndrome. It’s the new name for what was previously called polycystic ovary syndrome (PCOS). The name has changed, but the condition hasn’t, and understanding it properly has never mattered more. PMOS affects an estimated 1 in 8 women and people with ovaries worldwide, more than 3.1 million in the UK alone. Despite being one of the most common hormonal conditions, it remains widely misdiagnosed, misunderstood, and undertreated. On average, it takes two years and multiple doctor visits to get a diagnosis. You deserve better than that. This guide covers everything: what PMOS actually is, what causes it, what it feels like, how it’s diagnosed, and what you can do about it. Quick facts: What is PMOS? P – PolyendocrineM – MetabolicO – OvarianS – Syndrome Let’s break that down: Polyendocrine means more than one hormone system may be involved. PMOS can affect reproductive hormones such as testosterone, LH and FSH, but it may also affect insulin, thyroid hormones, cortisol and other metabolic pathways. Metabolic refers to the way your body processes energy, sugar and insulin. Many people with PCOS/PMOS have some degree of insulin resistance, where the body has to produce more insulin to keep blood sugar stable. Ovarian reflects the fact that the ovaries may be affected, particularly ovulation. However, despite the old name “polycystic ovary syndrome”, you do not need to have cysts on your ovaries to have the condition. Syndrome means it is a collection of features that can look different from person to person. PMOS is the most common cause of irregular periods and ovulatory infertility in people with ovaries. It is also linked to an increased risk of developing insulin resistance and longer-term health risks including type 2 diabetes, cardiovascular disease, endometrial cancer, anxiety and depression. Is PMOS the same as PCOS? PMOS is just the newer name being used for PCOS. For years, the condition was called polycystic ovary syndrome (PCOS), but that name has always been a bit misleading. Not everyone with PCOS has polycystic-looking ovaries, and not everyone with polycystic-looking ovaries has PCOS. The condition also affects far more than the ovaries. The shift towards PMOS aims to better reflect the full-body nature of the condition, including its links with insulin resistance, androgen excess, metabolic health, cardiovascular risk, mental health and fertility. That said, PCOS is still the most widely recognised search term, and most NHS, NICE and clinical guidance currently still uses PCOS. So, for now, you may see both terms used: PCOS = the older, widely used namePMOS = the newer, more accurate name You can read more about why PCOS was renamed PMOS here. What causes PMOS? The exact cause of PMOS isn’t fully understood, but research points to a combination of genetic, hormonal and metabolic factors. It tends to run in families, and if your mother, sister or aunt has PMOS, you might be at a higher risk. At its core, PMOS involves a dysfunction in the way the body produces and responds to hormones, particularly androgens and insulin. Androgen excess – the ovaries (and in some cases the adrenal glands) produce higher levels of androgens than normal. Androgens are often called “male hormones,” but they play important roles in everyone’s body. In PMOS, elevated androgens disrupt the normal development of follicles in the ovaries, preventing regular ovulation. Insulin resistance – the majority of people with PMOS have some degree of insulin resistance, meaning their cells don’t respond efficiently to insulin. This causes the pancreas to produce more insulin to compensate, and elevated insulin in turn stimulates the ovaries to produce more androgens, creating a self-reinforcing cycle. Disrupted pituitary signalling – the hormonal signals from the brain to the ovaries are altered in PMOS. LH (luteinising hormone) is often disproportionately elevated relative to FSH (follicle-stimulating hormone), which further disrupts follicle development and ovulation. Genetic factors – PMOS can run in families, suggesting genes play an important role. Researchers are trying to identify which genes are involved, but because it’s a complex condition, it’s not surprising that it’s not a single gene, but that many genes are involved. What are the symptoms of PMOS? PMOS presents differently  from person to person. Some people have many symptoms; others have very few. Some symptoms are visible; others are internal. This variability is one of the reasons it takes so long to diagnose. Irregular or absent periods Irregular menstrual cycles are one of the hallmark features of PMOS. Because elevated androgens interfere with regular ovulation, periods can arrive unpredictably, sometimes weeks late, sometimes skipped altogether. Some people experience very long cycles (35 days or more); others may go several months without a period. What counts as irregular? Cycles shorter than 21 days or longer than 35 days, fewer than 8 periods per year, or periods that have no predictable pattern. If your periods have always been irregular  or if they became irregular after stopping the pill, PMOS is one of the first things worth looking into. Hormonal acne Hormonal acne is one of the most common and most distressing symptoms of PMOS. PMOS-related acne typically appears along the jawline, chin and lower cheeks. It may flare around the time of a period, or it may be persistent and seemingly random. It tends to involve deeper, more inflamed spots rather than surface-level break out, and it often doesn’t respond well to standard skincare. If you’ve tried everything on your skin and still can’t get it under control, your hormones are worth investigating. Unwanted hair growth (hirsutism) Elevated testosterone stimulates hair growth in areas where most women don’t typically grow coarse hair, the upper lip, chin, jaw, chest, stomach and inner thighs. This is called hirsutism, and it affects a significant proportion of people with PMOS. It can range from fine, barely noticeable hair to […]

If you have been diagnosed with PCOS or suspect you have PMOS, you might have seen the news this week. On 12 May 2026, a landmark paper published in The Lancet officially renamed polycystic ovary syndrome (PCOS) to polyendocrine metabolic ovarian syndrome, or PMOS. It’s one letter different in the acronym. But the reasoning behind it, and what it means for diagnosis, treatment and the millions of people living with this condition, is significant. Here’s everything you need to know. Why has PCOS been renamed? The short answer: because the old name was wrong and that had real consequences. “Polycystic ovary syndrome” implies the condition is defined by cysts on the ovaries. In reality, those are not actually pathological ovarian cysts. What is visible on ultrasound are small antral follicles – immature follicles that haven’t developed properly, not cysts in the clinical sense. Describing the condition by a feature it doesn’t actually have has caused confusion among patients and clinicians alike for decades. More importantly, the old name obscured what PCOS actually is: a complex, whole-body hormonal and metabolic condition that affects far more than the ovaries. The new name recognises that the condition is not  primarily a gynaecological disorder, but instead a complex, multisystem condition involving endocrine, metabolic, reproductive, dermatological and psychological health. The name PCOS is misleading – it focuses on ‘cysts’ and the ovaries, when the condition is much more complex than that. This has led to missed diagnoses and people not getting the right treatment. For an estimated 1 in 8 women worldwide – over 170 million people – that’s not a semantic issue, it’s a healthcare one. What does PMOS stand for and what does it mean? PMOS: Polyendocrine Metabolic Ovarian Syndrome Each word in the new name is deliberate: Polyendocrine – reflects that this is fundamentally a hormonal condition, involving multiple endocrine disruptions. People with PMOS have a disturbance in the endocrine (or chemical messenger) system of the body, which can lead to widespread impacts. This includes abnormalities in androgen production, insulin signalling, ovarian hormone regulation and neuroendocrine function. Metabolic – acknowledges the significant metabolic dimension of the condition, including insulin resistance, diabetes risk and cardiovascular risk. For many people with PMOS, the metabolic features are as impactful or more so than the reproductive ones. Ovarian – retained in the new name because the ovaries remain central to understanding the condition. Abnormalities in follicle development and ovulation are all key features of PMOS. The ovary is involved, it’s just not the only thing going on, and it’s not cysts that define it. Syndrome – correctly reflects that this is a cluster of features, not a single-cause disease. How did changing PCOS to PMOS happen? This wasn’t a quick decision. The name change followed more than a decade of vigorous debate and the most robust disease-renaming process in history. The process was led by Professor Helena Teede, Director of Monash University’s Monash Centre for Health Research & Implementation, alongside the International Androgen Excess and PCOS Society, 56 patient and professional organisations including Verity PCOS UK  and garnered more than 22,000 survey responses from patients and multidisciplinary health professionals across all world regions. The revised name was introduced in a paper published in The Lancet and presented at the European Congress of Endocrinology in Prague. “It is fantastic that the new name now leads with hormones and recognises the metabolic dimension of the condition.” – Rachel Morman, Chair of Verity PCOS UK How is PMOS diagnosed? Nothing about the diagnostic criteria has fundamentally changed. If you were diagnosed with PCOS, that diagnosis still stands. The condition is the same, the name is what’s changing. To receive a PMOS/ PCOS diagnosis, a person must meet at least two of the following three criteria: 1. Irregular or absent menstrual cycles. Irregular cycles indicate that ovulation is not occurring regularly, a key feature of PMOS/ PCOS. According to the 2023 International Evidence-Based PCOS Guidelines, irregular cycles are defined as fewer than eight cycles per year, or cycle intervals outside the 21–35 day range, in women who are at least three years post-menarche (which is your first period). 2. Clinical or biochemical signs of high androgens (hyperandrogenism). This means either physical symptoms associated with elevated androgens such as excess facial or body hair (hirsutism), acne, scalp hair thinning or elevated androgen levels on a blood test – typically testosterone.  3. Polycystic ovarian morphology (PCOM). This refers to the appearance of the ovaries on an ultrasound scan, specifically a high number of small antral follicles (the immature follicles that house eggs) in one or both ovaries, or an increased ovarian volume. Alternatively, a high AMH (anti-Müllerian hormone) level on a blood test can be used as a marker of PCOM when an ultrasound isn’t available or appropriate. Crucially, “60% of women with the condition only need those first two – they don’t need the ovaries assessed in any way,” says Professor Teede. “For the other 30–40%, they can either have a blood test or an ultrasound, and arguably, a blood test is actually cheaper and much more convenient than an internal ultrasound.” The conversation about your condition should broaden For too long, people with PCOS were told it was “just about your periods” or “just a fertility issue.” The new name makes explicit that PMOS involves the endocrine system, metabolism, skin, mental health and cardiovascular health, not just the ovaries and reproductive function. “Language matters in medicine. The previous name often led to misconceptions and stigma, particularly around fertility. This change helps shift the conversation toward overall health rather than a single aspect of the condition.” – Dr Melanie Cree What actually causes PMOS and what does it affect? The name change is an opportunity to understand PMOS more completely. It’s not a condition that starts and ends with your cycle. Hormonal disruption (the “polyendocrine” part) PMOS involves elevated androgens like testosterone which can disrupt ovulation, cause acne, trigger unwanted hair growth (hirsutism) and contribute to hair thinning. The androgen […]

Polyendocrine metabolic ovarian syndrome (PMOS) is the condition you may still know as polycystic ovary syndrome (PCOS). It’s one of the most common hormonal conditions, affecting around 1 in 8 women. But despite the old name, it has never been just about the ovaries. PMOS can affect your periods, ovulation, skin, hair, metabolism, fertility, sleep and mental health. It can also look completely different from one person to another. One person may have very irregular periods and excess facial hair, while another has acne, fairly regular cycles and no obvious symptoms until they start trying to conceive. That variation is one of the reasons PMOS can be difficult to recognise and why diagnosis is sometimes delayed. Whether you have recently been diagnosed, think your symptoms could be linked to PMOS, or have been living with the condition for years, this guide covers PCOS symptoms, diagnosis, fertility, treatment, nutrition and long-term health. Quick facts:  If you are wondering whether your symptoms could be linked to PCOS, Hertility’s Advanced Hormone and Fertility Test can help build a clearer picture of your hormones, cycle and symptoms to help you understand what’s going on. Why was PCOS renamed PMOS? On 12 May 2026, the international PCOS community officially adopted the name polyendocrine metabolic ovarian syndrome, or PMOS. The previous name, polycystic ovary syndrome, could be misleading for several reasons. Firstly, the “cysts” associated with PCOS are not typical ovarian cysts. They are usually small ovarian follicles containing immature eggs. Secondly, you can have the condition without having polycystic-looking ovaries at all. Most importantly, the old name placed the emphasis on the ovaries when the condition can affect much more than reproductive health, including metabolism, hormones, mental wellbeing and long-term health. The new name was developed through an international process involving healthcare professionals, researchers and people living with the condition. If you already have a PCOS diagnosis, you do not need to be diagnosed again. Your diagnosis has not changed. You will also continue to see the term PCOS in medical records, research and online searches, which is why we use both PCOS and PMOS throughout this guide. Read more: PCOS has been renamed PMOS — here’s what that means for you. How common is PCOS? The World Health Organization estimates that PMOS affects up to 13% of women of reproductive age, making it one of the most common hormonal conditions worldwide, and that up to 70% of those affected may not know they have it. In the UK, the NHS estimates it affects about 1 in every 10 women. Part of the problem is that there’s no single way it presents. Diagnosis can also take time. In one international study, over a third of people with PCOS waited more than two years for a diagnosis, and almost half saw three or more health professionals before getting one. What are the common symptoms of PCOS? PCOS symptoms can affect your menstrual cycle, skin, hair, metabolism, sleep, mood and fertility. You do not need to have every symptom to have the condition. Menstrual cycle-related symptoms One of the most common features is irregular ovulation. which can make periods longer, unpredictable or absent for months, sometimes with heavier or prolonged bleeding after a long gap.  You may ovulate later, less often, or not at all in some cycles (an anovulatory cycle). In adults more than three years past their first period, cycles shorter than 21 days, longer than 35 days, or fewer than eight a year are considered irregular. Having regular periods don’t completely rule out PCOS, though more on that below.  If you want to understand your own cycle, see our guide Menstrual Cycle 101: Your Complete Guide to How Your Cycle Works Skin and hair-related symptoms Higher androgen activity (androgens include hormones like testosterone) can contribute to acne, oily skin, excess facial or body hair (known as hirsutism), often on the chin, upper lip, chest, abdomen or back, and scalp hair thinning, often noticed as a widening parting.  Hair-growth patterns vary a lot between individuals and ethnic groups, which matters when symptoms are assessed. Some people also develop acanthosis nigricans, darker, thicker, velvety-looking skin around the neck or underarms, which can be linked to insulin resistance. To find out more about how hormones affect your skin, read our guide to skin and hair changes. Weight gain or difficulty losing weight Some people experience weight gain or find weight harder to manage, but you don’t need to be overweight to have PCOS. It affects people across all body sizes, and insulin resistance can occur in people who aren’t overweight. Fatigue and sleep problems Significant tiredness is common, although fatigue has many causes and shouldn’t automatically be blamed on hormones. Obstructive sleep apnoea is more common in PMOS, even after taking BMI into account. So if you snore, wake up unrefreshed or feel tired all day, it’s worth talking to a healthcare professional. Mental health-related symptoms PCOS isn’t only physical. Depression and anxiety are more common, and symptoms like acne, unwanted hair growth, fertility difficulties, body-image concerns and weight stigma can all affect quality of life. Current guidance recommends that psychological wellbeing forms part of PMOS care, including screening and support for depression, anxiety and eating disorders. Difficulty conceiving PCOS is a leading cause of irregular ovulation and anovulatory infertility. If ovulation happens less often, there are fewer chances for egg and sperm to meet. But that’s very different from saying everyone with PCOS is infertile; many conceive naturally, and effective treatments exist when ovulation needs support. What causes PCOS? There is no single known cause of PCOS. Instead, it appears to develop through a combination of genetics, hormone signalling, ovarian function, metabolism and environmental factors. Two factors that are particularly important are androgens and insulin. High levels of Androgens Androgens are a group of hormones, the most common being testosterone. They are produced mainly by the ovaries and adrenal glands and have roles in reproductive health, bone and muscle health, sexual function and wider physiology. […]