Endometriosis is a common condition in women of childbearing age. Around 5% of women suffer from it, but this figure is as high as 25% in women with fertility problems.
Why does endometriosis occur?
Endometriosis is caused by the presence of endometrial tissue (the tissue that is shed with each menstruation) outside of the uterus. The disorder can occur in many parts of the human body, but it is most frequent in the pelvic area: peritoneum, ligaments, bladder, rectum, and above all in the ovaries. This last one, ovary endometriosis, gives rise to chocolate cysts.
What are chocolate cysts?
During menstruation, the ovary’s endometriotic tissue generates a small amount of blood which, over the years, forms cysts of old blood which gradually degrade and appear chocolaty in colour. The photo shows an example of normal follicular fluid (somewhat stained with blood as is natural during ovulation or during an IVF ovarian puncture), and the colour of the endometriotic chocolate cyst fluid.
In addition to fertility issues, the main symptoms are pelvic pain and menstrual irregularities.