Endometriosis is a condition in which tissue that should be inside your womb grows on the outside. This tissue is most often found around the pelvis, for example, around the fallopian tubes and the ovaries; however, it is sometimes found in the chest area and the gastrointestinal tract. This tissue is still controlled by the same hormones that control your period, which means that the tissue will still thicken and shed (bleed) as it does in a normal menstrual cycle. As a result, symptoms of endometriosis include pain when menstruating (known as dysmenorrhea), nausea, and general pelvic pain.

Endometriosis needs to be diagnosed and treated by a doctor.