Millions of women around the world suffer from period pain every month.
But their options are limited. If women experience mild period pain, they can take painkillers such as ibuprofen and paracetamol or mefenamic acid (a prescription only pill, commonly known as Pontac).
It’s no wonder that doctors and experts are now pointing out the remarkable lack of research and understanding around period pain. Indeed, new NHS guidelines say that women suffering with period pain should be checked for signs of endometriosis - a painful womb condition they say is going undiagnosed for an average of seven-and-a-half years, during which time it becomes harder to treat.
NHS watchdogs are concerned that GPs are missing too many cases of the condition, which occurs in around one in 10 women of reproductive age and can damage fertility.
In March, the All Parliamentary Group on Women's Health said 40 per cent of more than 2,600 women who gave evidence to it reported they had seen a doctor 10 times before being diagnosed.
The lack of understanding means that some women can have serious medical issues passed off as 'women's problems'
Endometriosis occurs when tissue that behaves like the lining of the womb is found in other parts of the body. This lining can start to cover the ovaries, fallopian tubes, parts of the stomach and bladder or bowel. Symptoms include chronic pelvic discomfort, extremely painful periods and pain during bowel movements or during or after sex.
In the new guidance, doctors are told to consider endometriosis in women reporting even just one symptom, such as pelvic pain or period pains which are bad enough to affect daily activities or quality of life.
John Guillebaud, professor of reproductive health at University College London, says that period cramping can be as “bad as having a heart attack.”
“Men don’t get it and it hasn’t been given the centrality it should have,” he told Quartz last year. “I do believe it’s something that should be taken care of, like anything else in medicine.”
Period pain, known as primary dysmenorrhea, interferes with the daily life of around one in five women, according to the American Academy of Family Physicians. Yet there has been little research into how to treat it and the signs that it could point to a more serious condition can be missed - or dismissed.
Dr Imogen Shaw, a GP specialising in women’s health, explains: “In general, there isn’t much research done into women’s health.
“I wouldn’t say dysmenorrhea has been hugely investigated.”
Does she think there would be more work looking into period pain if men were affected by it? “I suspect there would be, being very cynical,” she says.
The lack of understanding around menstrual health means that some women can have serious medical issues passed off as 'women's problems', by GPs.
In 2015, 21-year-old Kirstie Wilson died from cervical cancer. But before she was diagnosed, doctors put her painful stomach cramps down to “growing pains or thrush.”
Other women have reported being sent away by GPs, with painkillers and advice to use hot water bottles – though some were later found to be suffering from endometriosis.
The NHS website states:“there is no cure for endometriosis and it can be difficult to treat.”
But as Caroline Overton, chairwoman of the guideline committee and a consultant gynaecologist, said: "helping affected women manage their symptoms is imperative."
Dr Shaw adds that women's health can be seen as less of a priority than men’s. She says that she often has supply issues with hormonal treatments for women such as HRT patches and oestrogen creams, as manufacturers don't make enough.
"[Pharmacists] often don’t have them in or treatments will be stopped by manufacturers – not because of their performance but for financial reasons,” she says.
“You rarely find those supply problems with drug treatments for men’s health.”