Endometriosis is a chronic, benign, estrogen-dependent disease characterized by endometrial tissue that is implanted outside the uterus into the ovaries, intestines, or peritoneum but also outside the pelvis. It is a common disease that affects 7-10% of women around the world. The most common symptoms are pain and infertility. The diagnosis is histological after removal of lesions with laparoscopy (sensitivity 94%, specificity 79%), and treatment is symptomatic. At present, there is not a laboratory test that allows early and adequate diagnosis of endometriosis and therefore it can take up to 10 years for a patient to be diagnosed and patients often suffer from the disease. The purpose of our study is to investigate biomarkers associated with endometriosis and prove their use in the diagnosis and staging of endometriosis. The biomarkers will be studied even in relationship to clinical manifestations of the disease, as markers of relapse and as fertility markers. Meanwhile, quality of life of patients with advanced stages of endometriosis postoperatively will be studied.