Painful periods, infertility, ovarian cysts- endometriosis is no joke, and it affects about 10% of women. About half of women with infertility have endometriosis, and it's the second leading reason for hysterectomy. The disease costs $22 billion a year in the US alone. You might imagine that such a common disease is easily diagnosed in the clinic. However, the gold standard for diagnosing endometriosis is surgery to view the inside of the pelvis to look for the disease. A blood test for CA-125 might be high, but this test isn't very helpful because of the high rate of false positives and negatives. Fortunately, new research is uncovering biomarkers that may one day become the standard for diagnosing chronic endometriosis.