An MP has told how a painful cyst on one of her ovaries ruptured twice on separate occasions forcing her to miss two "crucial Brexit votes".
Louise Haigh, Labour MP for Sheffield Heeley, was in hospital twice with "excruciating pain" over the last year.
During a debate in Westminster Hall earlier, Ms Haigh said her experiences were "unfortunately far too common".
She said there was a "lack of education, awareness and medical research" on women's health issues.
Speaking at the parliamentary debate on endometriosis workplace support, the shadow policing minister said: "Last year during a round of crucial Brexit votes I collapsed in the opposition whips office and was taken to A&E.
"I ended up staying in St Thomas's [hospital] for almost a week, hooked up to an IV [intravenous machine] and pumped full of antibiotics and painkillers before I was eventually diagnosed with a cyst on one of my ovaries, having ruptured and caused an infection.
"Last week, during a similar round of crucial Brexit votes - feeling very much like groundhog day - I was back in A&E again with the same problem and in excruciating pain."
Ms Haigh said she was sent home with painkillers and told "cysts rupture in women all the time", before telling the debate it took her a long time to seek treatment but was "shrugged off".
"On leaving hospital last week I cried all the way home, in part because of the pain but mostly because I was furious that I had been so instantly dismissed and that I had been told that I simply had to live with this syndrome which could cause so much pain and risk on a monthly basis."
She called for discussions on periods to be normalised, adding the lack of education and research "tells us that our pain is less important and that our fertility is irrelevant".
Minister for Women's Health Caroline Dinenage said awareness of "painful and debilitating menstrual conditions is increasing - but there is still a long way to go".
She urged clinicians and employers to help "break down the ongoing stigma" and create "supportive and flexible ways to help those living with these conditions".