https://www.youtube.com/watch?v=tFAH9kGdt1UEndometriosis is a disease of the female reproductive system in which cells similar to those in the endometrium, the layer of tissue that normally covers the inside of the uterus, grow outside the uterus.[6][7] Lesions can be found on ovaries, fallopian tubes, tissue around the uterus and ovaries (peritoneum), intestines, bladder, and diaphragm; it may also occur in other parts of the body. Some symptoms include pelvic pain, heavy periods, pain with bowel movements, painful urination, and infertility.[1] Nearly half of those affected have chronic pelvic pain, while in 70% pain occurs during menstruation.[1] Pain during sexual intercourse is also common.
There are multiple causes of pain. Endometriosis lesions react to hormonal stimulation and may "bleed" at the time of menstruation. The blood accumulates locally if it is not cleared shortly by the immune, circulatory, and lymphatic system. This may further lead to swelling, which triggers inflammation with the activation of cytokines, which results in pain. Another source of pain is the organ dislocation that arises from adhesion binding internal organs to each other. The ovaries, the uterus, the oviducts, the peritoneum, and the bladder can be bound together. Pain triggered in this way can last throughout the menstrual cycle, not just during menstrual periods.
Rarely, endometriosis can cause endometrium-like tissue to be found in other parts of the body. Thoracic endometriosis occurs when endometrium-like tissue implants in the lungs or pleura. Manifestations of this include coughing up blood, a collapsed lung, or bleeding into the pleural space.[10][32] Endometriosis may also involve the nearby colon which in rare situations may progress to partial obstruction requiring emergency surgery.[33]
>TFW you cough up your own period blood 
