Differences in immune cells may explain why chronic pain lasts longer in women than men, according to new research.

The study identified a subset of monocytes, a type of white blood cell, that release interleukin-10, or IL-10, a molecule that signals pain-sensing nerves to switch off pain. These cells were found to be more active in males, linked to higher levels of sex hormones such as testosterone.

Females experienced longer-lasting pain and slower recovery because their monocytes were less active. The same pattern was observed in both mouse models and human patients.

Researchers first detected unexpectedly higher levels of IL-10 in males during a small pilot project. When a second test confirmed the finding, they used high-dimensional spectral flow cytometry, a laboratory technique that allows detailed analysis of immune cells, to investigate further. Blocking male sex hormones produced the opposite effect.

Geoffroy Laumet, associate professor of physiology at Michigan State University, said: “The difference in pain between men and women has a biological basis. It’s not in your head, and you’re not soft. It’s in your immune system.”

Pain occurs when specialised neurons throughout the body respond to stimulation. In people with chronic pain, these sensors can be activated by mild stimulation or even none at all. Doctors often rely on patients rating pain on a scale of one to 10, and when more women report persistent pain, the difference has often been attributed to perception or reporting rather than biology.

The team carried out at least five types of tests in mouse models to confirm the findings. They then worked with Sarah Linnsteadt at the University of North Carolina at Chapel Hill, who was studying psychological outcomes in people involved in car accidents. Her research showed a similar pattern, with men having more active IL-10-producing monocytes and resolving pain faster.

Jaewon Sim, a former graduate student in Laumet’s laboratory, said: “I feel extremely fortunate that we trusted those early, uncertain findings and chose to pursue them further.”

Laumet said: “This study shows that pain resolution is not a passive process. It is an active, immune-driven one.”

The findings shift attention from how pain begins to why it persists. The next step is to investigate whether treatments could target this pathway and boost IL-10 production. While any new treatment is likely to be decades away, the research could eventually support non-opioid approaches to managing chronic pain.

“Future researchers can build on this work,” Laumet said. “This opens new avenues for non-opioid therapies aimed at preventing chronic pain before it’s established.”

Very heavy or very light periods may be linked to underlying health problems that affect quality of life and can influence fertility, according to medical experts.

Heavy menstrual bleeding is reported to have a major impact on daily life, with around two thirds of affected women seeking medical help. Beyond anaemia, which can cause fatigue, dizziness, pallor and a rapid heartbeat, heavy bleeding can lead to social and practical difficulties such as stained clothing, higher use of menstrual products and work limitations.

Doctors stress that the amount of bleeding itself does not directly affect fertility. Instead, abnormal bleeding can reflect underlying conditions, some of which can make it harder to become pregnant.

Raúl Villasevil, a specialist in obstetrics and gynaecology at San Carlos Clinical Hospital in Madrid, Spain, said: “The most frequent causes of heavy periods are polyps, fibroids, adenomyosis, some malignant tumours, ovulatory and coagulation problems, endometrial disorders, and certain medications.”

Very light periods can also signal problems, including uterine malformations, intrauterine adhesions, where scar tissue forms inside the womb, and anatomical abnormalities of the vagina. They may also point to ovulatory and hormonal disorders such as hyperprolactinaemia, which involves excess production of the hormone prolactin, or polycystic ovary syndrome. Once confirmed, these conditions can lead to symptoms including infertility.

To identify the cause of abnormal bleeding, Villasevil said doctors begin with a detailed personal and gynaecological history, followed by a physical examination and usually an ultrasound to assess the uterus and ovaries. Blood tests are also used to check for anaemia, coagulation status and hormonal function.

“This basic evaluation is often sufficient to establish the cause of the bleeding abnormality and to propose solutions. If this basic workup does not identify the cause, additional tests such as hysteroscopy or magnetic resonance imaging can be performed,” he added.

Hysteroscopy involves inserting a small camera into the womb to examine it from the inside.

In most cases, the cause of menstrual abnormalities can be identified and treated. A range of treatments allow a personalised approach for each woman, taking into account whether she wishes to have children, her age and her individual needs at different stages of life.

A former Accenture employee has won an appeal tribunal ruling after a judge said her endometriosis may amount to a disability under the Equality Act 2010.

A senior employment law judge last month quashed a 2022 tribunal decision that rejected claims brought by Sanju Pal, 43, against the consulting firm.

The judge found the original ruling did not properly consider whether Pal’s endometriosis, a condition where tissue similar to the womb lining grows elsewhere and can cause chronic pain, amounted to a disability under the Equality Act 2010.

The decision also said the ruling mischaracterised her reasons for dismissal and lacked evidence for some claims.

Pal has previously described how Accenture terminated her contract in 2019 despite her having a “cyst the size of a Coke can” on one of her ovaries, in what was a severe and chronic case of the condition.

For Pal, however, the fight is not over. The judgement ordered a fresh employment tribunal to reconsider her claims, and Accenture reserves the right to appeal.

The case has drawn attention since the appeal decision, with Pal appearing on BBC News and Radio as well as ITV News.

Pal said: “Whilst my faith was shaken after the initial employment tribunal, this judgement has restored it somewhat.

“Luckily, I got an appeals judge who finally heard me.

“A line one of my close friends said was ‘the system failed Pal’. Oh my God, just to hear and see that.”

She added: “I’m not surprised my case is making waves in the media, as there is no other case in the UK that has gone to this level of court, for a respondent that refused to concede.

“Of course it’s going to gain traction now, and I think women are absolutely outraged that this could be possible.”

Emma Cox, head of Endometriosis UK, suggested on BBC Radio 5 Live that Pal’s case will make a “real difference”.

She said: “It yet again highlights that endometriosis and its impact are not properly understood in the workplace, and the appeal ruling makes it quite clear that those living with endometriosis may be protected, and it should be considered.

“I also hope it gives a push to our campaigns, one of the things we are pushing for is to have menstrual health included in the employment’s rights act.”

Pal, who also referenced a government petition to introduce menstrual leave for those with endometriosis and adenomyosis, a related condition where tissue grows into the muscular wall of the womb, due to be debated in parliament, said far more needs to be done to acknowledge the reality of workplace discrimination.

She commented: “Those with endometriosis are hearing from their employer: ‘What do you mean you can’t come into work? What do you mean you can’t do this shift’? Or ‘what do you mean that you need to take time off for X, Y and Z?’

“It’s happening every day across this country to millions of women, and that’s just endometriosis before you start talking about other conditions.”