Women suffering from endometriosis aren't being diagnosed quickly enough and treatment is of an "unacceptable" standard, according to new report by MPs.
Their investigation, chaired by the All Parliamentary Group on Women's Health, involved capturing the experience of over 2,600 women affected by the condition.
Around 40% said they had seen a doctor ten times before being diagnosed. Many said that they had to do their own research online to understand their symptoms.
Endometriosis affects around two million women, mostly aged between 25 and 40, in the UK.
It is a chronic illness with symptoms that can include period and lower back pain, pain before or after sex, bleeding between periods and difficulty getting pregnant.
Its cause isn't fully understood, but it is thought that the womb lining doesn't leave the body fully during a period, and instead embeds itself on pelvic organs.
Endometriosis is diagnosed via a surgical examination and can be treated with painkillers and hormone medication. But there's no known cure and it can be difficult to deal with, both physically and emotionally.
The MPs' report out this week found that women who suffer from the condition are often dismissed by doctors. Around 42% of women interviewed claim they were not treated with dignity and respect when they sought help from healthcare professionals.
However, the illness is gaining more visibility thanks to the efforts of bloggers and celebrities who have opened up about their battles with it.
Katie, 25, documents her experience with endometriosis on Instagram, under @MyEndometriosisJourney. She visited GPs nine times before being diagnosed.
"I went to the doctor so many times and I kept going back," she says. "One doctor told me to stop doing sit-ups because it was all muscular.
"I struggled a lot when I was at school and I would just pray that my period would come at the weekend so I wouldn't have to miss school and I wouldn't have to miss work."
Girls creator Lena Dunham also suffers from endometriosis.
"I’ve been hurting more and more. I started antibiotics, didn’t do anything, and the pain in my back and my pelvis has become overwhelming," Lena said, in a podcast that documented a typical experience with the condition.
She said her symptoms - including severe cramps, bleeding, exhaustion and mood swings - had often been ignored as "female whining".
"During the worst of it, my father brought me to the ER, where they prodded my appendix and suggested it might be food poisoning and that we should go home and wait it out," she said. "My mother placed a pillow under my lower back, and I moaned in the guest room, where no one could hear me, my legs spread like a woman in labor."
It takes an average of seven and a half years to diagnose endometriosis in the UK. Campaigners say they hope this new report will herald changes in the system.
"The report highlights some really practical things we can do to reduce diagnose time and support women with this condition," Emma Cox, from Endometriosis UK, tells BBC's Newsbeat.
That includes "education in menstrual health in schools" and "education for GPs and raising awareness with the public".
If you suffer from endometriosis - or suspect that you do - seek help and support with Endometriosis UK.
READ MORE: Endometriosis Explained: What It Is & How To Manage It
READ MORE: Lena Dunham Speaks Out About Her Battle With Endometriosis