If you’re someone who has a period, then you already know how painful they can be for many people. Many students who menstruate have had to miss school due to period pain—if you never had to miss school, then you surely know someone (or many someones) who did.

One dad is hoping to change the way schools treat absences due to period pain (dysmenorrhea). Marcus Alleyne created a Change.org petition in honor of his daughter, Izzy, who needed to miss school due to her period.

Unfortunately, Izzy’s school doesn’t consider period pain a valid reason for missing school, so her absence went unexcused.

The Alleyne family lives in Cornwall, England, but the invalidation of period pain is pretty universal. He tells Sky News that Izzy was “doubled over in pain” and couldn’t sleep because of her pain, so her parents thought she should stay home from school to rest.

“We had the notion that if it [were] any other illness or condition it would have been documented as an illness rather than an unauthorized absence,” Alleyne says. He was wrong.

“I am the proud father of incredibly courageous, fierce and strong daughters, the eldest of which attends Secondary School,” Alleyne writes in the petition. “It not only saddens me that I am urged to write to you, but it also raises significant concerns surrounding the physical, mental and social wellbeing of not only my daughters but all people who have periods across the country.”

He says anyone who has had a period likely agrees that at some point, they’ve suffered from dysmenorrhea—which is a recognized condition in the medical community.

“By not allowing absences due to Dysmenorrhoea, which you are doing by considering them unauthorised, shows very clear disparities, and registering absences as unauthorised due to a medical condition only affecting women and people who menstruate is a clear demonstration,” he writes.

In the petition, Alleyne expands on the disparities and sexism at play when period pain is dismissed—particularly when cis men are making these decisions in schools.

“This leads me to the concerns I have surrounding ignorance of the condition, the impact of a CIS male-dominated field within the senior leadership teams in schools, or the sheer disregard for the physical, emotional and academic wellbeing of our pupils,” he continues. “As the department responsible for Education it baffles me that the following archaic approach is not only alive and well but also continuing to influence practice in 2021 posing a direct risk to our young women, trans, non-binary pupils and everyone pupil has by no choice of theirs own menstruates.”

The petition currently has nearly 70,000 signatures, with many people sharing their own experiences with dysmenorrhea. Hopefully, the Change.org petition brings actual change in school districts as well as awareness to this very common and very valid health issue.