A condition that affects more than three million women and girls in the UK has been given a new name to reduce the chances of missed diagnoses and inadequate treatment.

Polycystic ovary syndrome (PCOS), a common condition that impacts how a woman's ovaries work, will now be referred to as polyendocrine metabolic ovarian syndrome (PMOS).

PMOS is characterised by fluctuations in hormones, impacting weight, metabolic and mental health, skin, and the reproductive system.

It is the most common cause of anovulation - where an egg does not release from the ovary during a menstrual cycle - among women globally and a leading cause of infertility, according to the World Health Organisation.

Researchers and supporters of the change said the old name misrepresented what is a complex hormonal or endocrine disorder, often leading to a flawed focus on cysts and ovaries.

The name change process, outlined on Wednesday in The Lancet, has taken 14 years of global collaboration between experts and those who have lived with the condition, which affects one in eight women worldwide.

Professor Helena Teede, director of Monash University's Monash Centre for Health Research and Implementation in Australia, led the process after decades of research and seeing the old name's impact first-hand.

"What we now know is that there is actually no increase in abnormal cysts on the ovary, and the diverse features of the condition were often unappreciated," Professor Teede said.

"It was heart-breaking to see the delayed diagnosis, limited awareness and inadequate care afforded to those affected by this neglected condition."

Professor Teede said it was the largest initiative to change the name of a medical condition, describing it as a "landmark moment" that will lead to worldwide advancements in clinical practice and research.

"The agreed principles of the new name included patient benefit, scientific accuracy, ease of communication, avoidance of stigma, cultural appropriateness and accompanying implementation," she said.

What is PMOS?

The three main features of PMOS are: irregular periods, excess androgen, and polycystic ovaries. Signs and symptoms usually become apparent during the late teens or early 20s.

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They can include: irregular periods or no periods at all; difficulty getting pregnant as a result of irregular ovulation or no ovulation; excessive hair growth; weight gain; thinning hair and hair loss from the head; and oily skin or acne.

PMOS is also associated with a greater risk of developing health problems in later life, such as type 2 diabetes and high cholesterol levels.

What causes the condition?

The exact cause is unknown, but PMOS often runs in families, and it is related to abnormal hormone levels in the body, including high insulin levels.

Many women with PMOS are resistant to the action of insulin and produce higher levels of insulin to counter this, contributing to the increased production and activity of hormones such as testosterone.

How can PMOS be treated?

There's no cure for PMOS, but symptoms can be treated.

If you have it and you're overweight, losing weight and eating a healthy, balanced diet can help with some symptoms.

There are also medicines available to treat individual symptoms, including excessive hair growth, irregular periods and fertility problems.

A simple surgical procedure called laparoscopic ovarian drilling may be recommended if fertility medicines are not effective.

(c) Sky News 2026: Leading infertility cause - polycystic ovary syndrome - renamed in push for better care