Many medical conditions are renamed. This can happen as we develop a greater understanding of a condition through research, as well as in response to changes in society. Recently Polycystic ovary syndrome (PCOS) has been one of those changes. On May 12, 2026, PCOS was renamed to Polyendocrine metabolic ovarian syndrome (PMOS) by the Global Name Change Consortium. This process took over 14 years and involved the input of thousands of patients and professionals. But does this change go beyond just the name of the condition? What does this mean for those diagnosed with ‘PMOS’?
PMOS is thought to affect around one in eight women. Some estimates suggest that up to 70% of people with the condition remain undiagnosed. The likelihood is that you probably know someone with PMOS, but perhaps they don’t know it themselves. Or maybe they have been trying to get a diagnosis for years.
PMOS is a lifelong hormonal and metabolic disorder affecting multiple body systems, including reproductive hormones, insulin regulation, and overall metabolic health.
To put it simply, PMOS can affect reproductive, hormonal and metabolic health, with effects that can be felt across different parts of the body. At the moment, there is no known ‘cure’. The cause of PMOS also remains unclear. There are some theories that it could have a genetic component - if someone in your family like your mother, auntie or grandmother has PMOS, you could have a higher chance of having PMOS.
What does PMOS look like?
Many women are diagnosed with PMOS in their late teens, early 20s because they start experiencing difficulties with their menstrual cycle (periods).
Other signs and symptoms include:
- Weight gain
- Polycystic ovaries (on ultrasound scan)
- Irregular periods or no periods (amenorrhoea)
- Acne
- Hair thinning on head
- Facial hair (Hirsutism)
- Fatigue
- Heightened anxiety & stress
- High levels of androgens (such as testosterone)
- Issues with fertility
The Rotterdam criteria, introduced in 2003, helped recognise different clinical presentations of PCOS. These are often described as four phenotypes:
- Phenotype A (Classic / Complete): Hyperandrogenism + Irregular Periods + Polycystic Ovaries
- Phenotype B (Classic / Non-PCO): Hyperandrogenism + Irregular Periods (without polycystic ovaries)
- Phenotype C (Ovulatory): Hyperandrogenism + Polycystic Ovaries (with regular periods)
- Phenotype D (Non-Hyperandrogenic / Normoandrogenic): Irregular Periods + Polycystic Ovaries (without high androgens)
Why the name change?
‘Polycystic ovary syndrome’ sounds pretty scary. The ovarian appearance associated with ‘PCOS’ is generally an increased number of small follicles (fluid-filled sacs containing a single, immature egg cell) rather than ‘ovarian cysts’. And as we know from the Rotterdam Phenotypes, some women diagnosed will not have polycystic ovaries present (phenotype B).
So how can we use a term such as ‘polycystic’ when the ovarian appearance associated with the condition generally refers to multiple small follicles rather than ovarian cysts? The name PCOS does not reflect the condition.
Not only does the condition not involve ‘cysts’ but it affects much more of the body than just the ovaries. The metabolism, hormone systems, and mental health are all a large part of the condition.
The name ‘PCOS’ could contribute to confusion and stigma, particularly because it places the focus on the ovaries and the word ‘cysts’.
So why ‘polyendocrine metabolic ovarian syndrome’?
PMOS more accurately reflects the complexity of the condition. Let’s break it down:
- Polyendocrine: There are ‘many’ (poly) hormone systems involved in the condition such as androgens, cortisol, and insulin.
- Metabolic: How the body processes energy. This can link to insulin resistance, type 2 diabetes and cardiovascular health.
- Ovarian: A component of the female reproductive system. Causing potential problems with periods and fertility.
- Syndrome: A group of symptoms that happen together. PMOS will look different in every person.
A condition that does not just affect ovaries, but has an impact on numerous systems in the body.
What does this mean for women with ‘PMOS’?
For many people, reaching a diagnosis can be a lengthy process. This may be one contributing factor to estimates suggesting that up to 70% of people with the condition remain undiagnosed.
What could change?
Clinical language
Doctors may increasingly think of PMOS as a condition involving reproductive, endocrine and metabolic health rather than primarily an ovarian disorder.
Research
The new terminology could help researchers and funding bodies frame PMOS as a multisystem condition.
Patient understanding
Removing “cysts” from the name may help patients understand that the condition is not simply about cysts on the ovaries.
What won’t necessarily change overnight?
A name doesn’t automatically:
- create new treatments
- shorten waiting lists
- eliminate diagnostic delays
- change someone’s symptoms
- provide a cure
- guarantee better care
We do not however yet know if this name change will result in these outcomes.
The transition from PCOS to PMOS is happening over a three-year period. It is expected to be completed during the 2028 International Guideline update.
For now, women’s health conditions like PMOS are receiving more recognition and attention they require. For years, women have suffered from conditions that they may not even know they have.
No matter how small the symptom, it is always worth checking it out. We get so used to pushing through and just ‘getting on with it’. But long term, this can be exhausting.
If you suspect you may have PMOS, don’t ignore it. Reach out for support, whether that is from a friend, a doctor or even a social media group. You are not alone.
A new name cannot, on its own, shorten a diagnosis, create a treatment or make someone feel heard. But it can change the way we talk about a condition.
The real test of PMOS will be whether that change in language is followed by changes in research, diagnosis, treatment and the experiences of the people living with it.
