What is endometriosis?

Endometriosis is when tissue, similar to tissue found inside the womb, is found elsewhere in the body. For some, this can cause severe symptoms, including painful periods and pelvic pain, and it could mean that people have difficulties getting pregnant.

Endometriosis can have a huge impact on a person’s quality of life, their work, and their relationships.

A diagram of the female reproductive organs showing spots of endometriosis tissue outside of the womb
Endometriosis is when tissue, similar to tissue found inside the womb is found elsewhere in the body

It’s estimated that endometriosis affects about one in ten women and those assigned female at birth. For the most part, it’s thought to affect people of reproductive age (generally between 11-45 years), but people who haven’t reached puberty yet or those who are older and have gone through menopause could also have the disease.

Endometriosis is usually found in the pelvis. The pelvis is the part of the body where the reproductive organs are located, e.g. the vagina, uterus, ovaries and fallopian tubes. This part of the body also contains the bowel and bladder. It’s not unusual for endometriosis to affect those organs too. Occasionally, endometriosis can be found outside of the pelvis, on other organs or structures in the body, including the diaphragm and lungs.

Endometriosis spots or ‘lesions’ cause irritation, bleeding, inflammation, and scarring wherever they are found. Sometimes they can cause organs to stick together with bands of scar tissue called ‘adhesions’.

Endometriosis can cause pain and other symptoms, often during menstrual periods. Over time, and as the disease progresses, these symptoms might be experienced throughout the month.

While we don’t yet know what causes endometriosis, research has shown that people are more likely to have the disease if their genetic mother or sibling has the disease.

A pie chart showing that 72.8% of endometriosis patients have a relative with endometriosis

Patient Perspectives

Our patient perspectives are taken from interviews with endometriosis patients and the 2018 survey

  • I'd never heard of endometriosis until I was diagnosed and it was the most isolating feeling, as if you’re sprung on by this condition and there’s no one who understands.
  • Endometriosis is an entirely invisible illness. Apart from being able to show people your scars from all the surgeries that you've had - which obviously you don't do because they're covered by your clothes - you look completely normal.
  • I didn’t know endo existed . . . I thought period pain was part of a woman’s lot. There are no comparators between women that would enable a woman to say, ‘something must be wrong, I feel worse than my counterparts’. . . again it’s due to lack of knowledge about endometriosis.

Pathway Perspective

Because the location, symptoms, and severity can vary so much, endometriosis is an extremely difficult condition to diagnose.