Understanding Endometriosis and how it changes the game

In recent years, many BWSL players, including England captain Leah Williamson, Tottenham Hotspur captain Bethany England, and Katja Snoeijs, have spoken about the symptoms of endometriosis and how it has changed the way they play football.

Endometriosis is a condition in which cells similar to those in the lining of the uterus grow in other parts of the body. It can have a significant impact on a woman's life. While it can grow anywhere, it's most often found in areas around the womb, such as the ovaries, fallopian tubes and lining of the pelvis. It can also affect other organs such as the bladder and bowel.

Symptoms occur when patches of endometriosis break down and bleed, but cannot leave the body during a woman's period. The pain can be severe and can stop them from doing normal activities. It can also cause heavy periods where they would need to change their sanitary products every one to two hours or maybe bleed through clothing.

Other symptoms are pain in the lower tummy and back, plus extreme tiredness. Statistically 1 in 10 women biological feamles of reproductive age UK have endometriosis.

The most recent BWSL player to speak about her experience with the condition is Katja Snoeijs, who told The Guardian she recalled being unable to stand up straight during a match because her symptoms were so unbearable.

Snoeijs joined Everton in 2022. The 29-year-old explained that she probably has had it since she was a teenager, but she brushed the symptoms around her period aside as just normal period pain. But this came to a head over the last two years, when it started to affect her on the pitch.

"Probably at the worst it feels like someone is continuously stabbing you in the stomach," the Netherlands international said.

Snoeijs added: "My lower back would always be really sore and really tight. I get a sickness feeling at some points where you feel like you're going to throw up."

The Dutch international reflected that: “There was one national team session where I couldn’t run, I was in so much pain. I felt like I had to throw up, and I had to leave the session. But even then, it was so hard to acknowledge something was not right.”

She also spoke about a recent endometriosis flare-up she had away from the pitch last Christmas, which kept her in bed for three days. Since then, at the beginning of 2026, she underwent keyhole surgery to confirm her endometriosis diagnosis, as laparoscopy is the only definitive way to diagnose the condition.

The Everton player expressed her concern that: “A lot of women either get told it’s normal period pain, or you think it yourself.”

“But we all know it’s not normal to lie in your bed for three days because of period pain.”

In 2021, Leah Williamson was sidelined with a hamstring injury and was diagnosed with endometriosis, later revealing her fear of missing the successful Euro 2022 campaign because of the condition.

She said in an interview with Women’s Health, “Before the Euros, I had a concussion, which they say can really impact your next period, and it was bad – like, really bad. You know when you’re on the bathroom floor and literally like: “I can’t move.” When it’s too late to take the tablets because I’m, like, in it now.”

In England's record-breaking 8-0 victory against Norway in the group stage of the Euros, the England captain feared an endometriosis flare-up before the fixture. “I was like, ‘It cannot happen. Like, I actually won’t be able to play.’ [Having an endometriosis flare-up] is a big fear when you get to a tournament, not injured…I don’t change too much around [my cycle] now. Unless I’m on the floor, and then I’m like: ‘I won’t make it today,’” Williamson explained.

“I’m a professional athlete, I’ve always been like, ‘let’s get on with it’”, which is how the lioness characterised how she dealt with the difficult periods.

Like Williamson, Snoeijs felt she needed to push through it: “As an athlete, it’s always hard to acknowledge when you feel something. It’s natural to ‘push through’. In your head, you’re thinking: ‘I can still do something’, but you’re only making it worse for your body.”

Bethany England, like many women in the UK, had to wait eight years in pain, which is the average wait time from a GP visit to diagnosis with this condition. (eight years 10 months)

She spoke to Sky Sports in 2024 about vividly remembering the day she passed out in a supermarket and was taken to the hospital in an ambulance.

She described experiences ranging from lying in bed in agony with a hot water bottle to spending time on the physio table after an endometriosis flare-up and watching from the sidelines as her team-mates trained.

When the Spurs player was diagnosed, her immediate question was, "Would I ever have kids?”

According to Endometriosis UK, the condition does not necessarily cause infertility. There is an association with fertility problems, although the exact link is not yet fully understood.

The 31-year-old underwent surgery to have her endometriosis removed, which she described as life-changing. She said: "but they never know fully how much it has affected your ovaries until they get inside you. As it stands, I've been cleared of endo, and it's not come back yet."

"I still get check-ups because if I go through patches where the pain has increased or decreased, I can manage it. But I've had times where I've had to go and make sure that everything is going as it should."

For England, everything changed after the surgery: "I can focus on my football and do my job. It's helped me in my day-to-day life knowing that even once a month I still get the same symptoms, the odd cramps, the back aches, the tiredness, it's having more of an awareness of managing it."

Surgery can alleviate some of the pain but there is no cure for the condition and symptoms are unpredictable.

Many football organisations like the FA, BWSL, UEFA and FIFPRO have all completed wider research on the menstrual cycle as a whole and its impact on player performance.