(The Economist) – Uteruses are lined with the endometrium, a layer of tissue that thickens during a menstrual cycle. If a fertilised egg does not become implanted, the lining thins and is shed as a period. If endometrial tissue grows abnormally outside the uterus, however, it can cause havoc. In extreme cases of endometriosis, adhesions can “bind” a woman’s organs together—from ovaries to bladder to bowels—and freeze them in place. Milder cases come with severe pain, heavy menstruation, inflammation and scar tissue caused by internal bleeding, fatigue and infertility. There is no known cure, and treatment focuses on controlling symptoms, normally through some combination of hormonal birth control, pain relief or surgery. (Read More)