More than 65,000 people have signed a petition for menstrual leave to be added to UK employment rights law.

The campaign needs 100,000 signatures for a parliamentary debate.

It was launched by Scots mum Michelle Dewar, who endured chronic pain for nine years before being diagnosed with endometriosis – a condition where tissue similar to the womb lining grows outside the womb.

Dewar wants the UK to follow Portugal, which recently introduced paid leave for people with similar conditions. She says protections must include no loss of pay, benefits or seniority.

Endometriosis UK has welcomed the petition but argues the government should go further and recognise menstrual health conditions such as endometriosis and adenomyosis as chronic diseases that deserve the same workplace support as illnesses such as diabetes or asthma.

Writing in the Scottish Sun, Emma Cox, chief executive of Endometriosis UK, said workplace discrimination remains widespread due to limited understanding.

“The taboo and embarrassment around ‘women’s issues’ makes the topic hard or impossible to discuss with managers,” she said.

Examples include fears about being made to wear light-coloured uniforms during heavy bleeding, fluctuating symptoms that lead to staff being unfairly labelled as “flaky”, and absence management policies that penalise people for their condition.

The charity says absenteeism caused by heavy and painful periods, endometriosis, fibroids and ovarian cysts costs the UK economy nearly £11bn each year.

Endometriosis UK is calling for the Employment Rights Bill to require menstrual health action plans in workplaces, giving staff clear guidance on support.

It also wants the NHS to cut diagnosis times, which average eight years and 10 months for endometriosis, and to extend that target to adenomyosis too, aiming for one year or less by 2030.

Cox warned that the term “menstrual leave” could be misleading.

She said: “We fear the term ‘menstrual leave’ could be misunderstood to imply it is for everyone who has periods and could lead to discrimination, or perpetuate the myth that it is ‘normal’ to have severe symptoms and that those who can’t cope are ‘weak’.”

The charity runs an Endometriosis Friendly Employer Scheme and workplace training to help organisations understand the impact of both endometriosis and adenomyosis.

Analysis of millions of health records shows endometriosis is connected to more than 600 conditions, including migraines, asthma and digestive disorders.

The research used algorithms to compare medical histories of people with and without endometriosis, confirming known associations and revealing new ones.

Scientists at the University of California, San Francisco examined data from the University of California’s Health Data Warehouse, which holds records for around eight million people from 2012 onwards.

Findings ranged from reproductive and autoimmune disorders to less-discussed conditions such as gastroesophageal reflux disease, asthma and vitamin D deficiency.

Endometriosis occurs when cells similar to those lining the womb grow outside it and on nearby organs.

Umair Khan is a PhD student in the biological and medical informatics programme at UCSF.

Khan said: “We identified hundreds of health conditions significantly associated with endometriosis, ranging from reproductive disorders and autoimmune diseases to migraines, asthma and gastrointestinal conditions.

“Many of these associations were present even before a formal endometriosis diagnosis, and almost half were replicated in an entirely separate dataset.

“We hope this study validates patients’ lived experience that endometriosis often comes with a variety of other health challenges.”

The large-scale approach allowed researchers to include millions of participants, making the study broader than previous research which usually focused on single conditions such as infertility.

Two notable findings stood out.

Women with endometriosis appeared less likely than others to have high cholesterol – which Khan described as “intriguing, given growing interest in statins as a potential treatment for endometriosis.”

Statins are cholesterol-lowering medicines that are also being explored for their potential to reduce the progression and symptoms of endometriosis.

The study also found a strong association with migraines, suggesting the two conditions may share biological pathways. Migraines often appeared in patients’ records before an endometriosis diagnosis.

Experts said the findings reinforce the view of endometriosis as a systemic disease, not just a pelvic disorder.

Inflammation, immune dysregulation and molecular signals such as microRNAs may help explain its widespread effects.

Research also suggests shared genetic pathways could account for links with conditions like migraine.

Clinicians note that understanding endometriosis as a whole-body condition highlights the importance of early recognition and management.

Patients may benefit from anti-inflammatory medicines not only for pain but to reduce broader systemic effects.

Researchers added that big data methods like those used here could help guide more personalised treatment strategies.

Work is now underway to apply predictive modelling and artificial intelligence to identify those at higher risk and to explore whether existing medicines can be repurposed for treatment.

A petition urging the introduction of paid menstrual leave for endometriosis and adenomyosis has gained more than 3,450 signatures across the UK.

The campaign calls for up to three days of statutory leave per month for those with a confirmed medical diagnosis of these chronic conditions, which affect around 1.5 million people nationwide.

It follows Portugal’s introduction of new legislation, due to take effect in 2025, that grants employees experiencing acute menstrual pain from these conditions up to three days of paid leave each month.

In the petition, campaigners said: “We call on the UK Government to introduce statutory paid menstrual leave of up to three days per month for people with conditions such as endometriosis and adenomyosis, following the model introduced in Portugal in 2025.

“We urge the UK Government to implement a statutory menstrual leave policy similar to the one recently passed in Portugal.”

If the petition reaches 10,000 signatures, the Government will issue a written response. At 100,000, it will be considered for debate in Parliament.

Though thought to affect around one in 10 women, endometriosis remains severely underdiagnosed.

Data from the Office for National Statistics (ONS) shows that between 2011 and 2021, only around 2 per cent of women of reproductive age received a diagnosis.

According to the ONS: “Using 2011 Census data linked to hospital records from 2011 to 2021, we estimate the prevalence of an endometriosis diagnosis to be approximately two per cent of reproductive age women in our linked population, with an average age at diagnosis of 35 years; this is likely an underestimate of the true prevalence, as many women will not have a diagnosis.”

Endometriosis UK states that the condition is the second most common gynaecological condition in the UK, yet it takes an average of eight years and 10 months from first GP visit to diagnosis.

According to the NHS, symptoms occur when patches of endometriosis break down and bleed during a period but cannot leave the body.

Adenomyosis may cause similar symptoms, although some people do not experience any.

Treatment options include painkillers and hormone therapies. In more severe cases, surgery may be offered.

For severe adenomyosis, this can include a hysterectomy or surgery to remove the womb lining.