Transcription
Translator: Selma Djaadi
Reviewer: Hani Eldalees
In 1920, Hungarian physician Béla Schick conducted a highly questionable experiment: he asked several women, some of whom were menstruating, to briefly hold flowers. Afterward, without proper controls and relying solely on his own observations, he claimed that flowers held by menstruating women wilted faster. Schick's explanation for this was not only unscientific but also played into ancient myths about menstruation. He concluded that the bodies of menstruating women excrete toxins, released in sweat and blood, that could kill plants.
While it unfortunately took decades to debunk Schick's so-called menstrual toxin hypothesis, some benefits did emerge from this work—the idea spurred investigations into the composition of menstrual fluid, ultimately leading to a discovery that helped explain a very real problem: menstrual cramps. Between 50 and 90% of menstruating women experience painful abdominal or pelvic contractions during their period, a condition known as dysmenorrhea. Individual experiences can vary, from mild discomfort, to throbbing pain, to labor-like cramping spasms. Cramping can extend to the back and thighs, and be accompanied by bloating, nausea, and even vomiting. For at least 10% of menstruating women, these symptoms are so severe that they disrupt their daily activities.
Healthcare experts classify dysmenorrhea into two main types: primary and secondary. For some, menstrual cramping can be traced to underlying conditions, including endometriosis, where tissue similar to the uterine lining grows outside the uterus, or uterine fibroids, which are noncancerous tumors. This type of pain is called secondary dysmenorrhea. While these conditions can be linked to specific medical issues, the origins of the pain are often poorly understood. For example, endometriosis can lead to scarring and inflammation, and fibroids can press on other organs, both of which can cause discomfort. However, the severity of cramping pain does not always correlate with the severity of these factors. And because the conditions are so variable, so is the treatment.
Primary dysmenorrhea, on the other hand, is more common, referring to painful menstrual cramps that cannot be linked to an underlying condition. Despite the misleading nature of Schick's experiments, they did chart a path toward a better understanding of this pain. While it’s clear that early researchers never found a menstrual toxin, in the 1960s and 70s, scientists studying menstrual fluid discovered compounds called prostaglandins. Further research showed that many women who experience painful menstrual cramps often have higher levels of prostaglandins in their menstrual fluid.
One of prostaglandins' important roles is to stimulate the uterine muscles to contract, a crucial step in shedding the uterine lining during menstruation. It is therefore thought that increased prostaglandins may intensify these contractions, causing pain. This process can also cause blood vessels to constrict, reducing oxygen flow and releasing chemicals that activate pain receptors. Because many over-the-counter pain medications, such as naproxen and ibuprofen, work by targeting prostaglandins, they can provide relief for some people experiencing menstrual pain. Others find hormone-based contraceptives that thin the uterine lining and in turn reduce prostaglandin production to be beneficial.
But while prostaglandin research has been foundational and shaped how we understand menstrual pain, it has become clear in recent years that prostaglandins are only part of the story. Many other factors likely contribute to painful cramping, including hormones, inflammation, brain pathways, and possibly even the microbiome. And because menstrual pain is not fully understood, current treatments don’t always work for everyone.
Furthermore, talking about menstrual cramps can be embarrassing or even taboo, leading many people to feel they simply have to endure the pain. But regularly suffering from severe cramping is far from benign. Some experts believe that repeated exposure to pain can cause the nervous system to become sensitized, making a person susceptible to chronic pain conditions. For this reason, more research is needed to unravel the complex drivers of this surprisingly common experience and develop better treatments. This work can start with acknowledging that menstrual pain is real, and it affects hundreds of millions of people.