Endometriosis is a condition where fragments of the lining of the uterus (endometrial tissue) become embedded, or implanted, elsewhere in the body.

Although not inside the uterus, this tissue responds to the hormonal changes that control menstruation. Like the uterine lining, these fragments build tissue each month, then break down and bleed. Unlike blood from the uterine lining, blood from implants has no way to leave the body. Instead the blood from the implants is absorbed by surrounding tissue which in turn causes pain.

All sites submitted to this category must be designed for use by teens, ages 13 to 18, and provide information on or about endometriosis.

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