What is endometriosis?

Endometriosis is a disorder in which bits of tissue from the inner lining of the uterus (the endometrium) grow inside a woman's body, outside of the uterus. The uterus is a hollow organ within a woman's abdomen where a fertilized egg implants and where a developing baby is nourished and grows.

Endometriosis can be an excruciatingly painful condition, and it can have a profound, debilitating effect on a woman's life. But despite this, many have never heard of it.

Typically, the most common symptom is acutely painful periods. And because of this, the pain is often just put down to the 'time of the month'.

An estimated 2 million women in the UK suffer from endometriosis – and Marilyn Monroe, Susan Sarandon and Louise Rednapp are all said to have had it.

Simply explained, endometriosis is a condition where cells, like the ones in the lining of the womb, are found outside the uterus.

Typically, these are found in the pelvic area – such as in the Fallopian tubes, ovaries, on the outside of the womb, or on the ligaments which hold the womb in place. They may also be found in the bowl, bladder, intestines or vagina.

Like womb cells, endometrial cells respond to hormone changes throughout the monthly cycle, swelling with blood and then breaking down causing internal bleeding. Since this internal bleeding has nowhere to go, it can cause inflammation and adhesions.

In rare cases, endometrial cells have been found in other parts of the body, such as the brain, lungs and eyes.

Endometriosis can lead to cysts and adenomyosis – a painful condition where endometrial tissue develops in the muscle layer of the womb