Endometriosis — a condition in which implants similar to the lining of the uterus are found outside the uterus and result in heavy, painful periods — is much more common than you think.
According to Endometriosis.org, 1 in 10 women has endometriosis — and 176 million people worldwide are affected by the disruptive condition. It is a serious but neglected public health issue. In fact, according to a National Institute of Child Health and Human Development-led study published in 2011, 11 percent of a group of women who had not been diagnosed with endometriosis had the disorder. And if the finding applies to all women in the United States, the number of American women with endometriosis could exceed previous estimates of 5 million.
Female celebrities aren't excluded from this figure, of course.
Several famous faces have started speaking out about their struggles with the sometimes-debilitating condition in an attempt to destigmatize the wider discussion surrounding menstruation.
A version of this article was originally published in June 2017.