Aim: based on a retrospective analysis, the relationship between external genital endometriosis and comorbid breast pathology was established and risk factors were identified, their comparison and the formation of a prognostic risk criterion were determined. Materials and Methods: to address the objectives of the study, a retrospective analysis of 470 cases of patients treated for external genital endometriosis after surgical treatment and comorbid breast pathology was conducted. The control group included 30 healthy non-pregnant women. Statistical processing was performed on a personal computer using the statistical software package Statistica 10. Results: As a result of the analysis, the age of the patients ranged from 23 to 40 years. The average age of patients in the study group was (32.2}1.18) years, and in the control group (31.1}1.35) (p>0.05). The groups were homogeneous in terms of age (p>0.05), marital status (p>0.05) and level of education (p>0.05). Close relatives in 208 (44.25}2.18) % (OR=8.86; 95 % CI: (0.68-10.53); p<0.002) cases suffered from benign (hormone-dependent) tumours and tumour-like diseases of the uterus and appendages in isolation or in various combinations (fibroids, adenomyosis, endometrial hyperplasia). It was also found that 102 (21.70}1.67) % of patients had endometriosis, which may indicate a genetic predisposition to this disease. In the closest relatives of EM patients: in 118 (25.10}2.01) % of the examined parents, breast problems were noted, in 66 (14.04}1.12) % – diabetes mellitus, and in 98 (20.85}1.22) % thyroid diseases were detected, which in total amounted to (60.00}2.23) % (OR=9.12; 95 % CI: (0.58-11.54); p<0.002). Early menarche almost tripled the risk of EM (OR=2.72; 95% CI: (1.02-5.11); p<0.002), and menstrual irregularities doubled it (OR=2.04; 95% CI: (1.09-3.14); p<0.05), higher education, urban residents – 2.2 times higher (OR= 2.27; 95 % CI: (1.11-3.63); p<0.05), diseases of the gastrointestinal tract and hepatobiliary complex – 5.2 times higher (OR=5.27; 95 % CI: (1.89-12.03); p<0.05), frequently recurrent inflammatory diseases of the appendages – 3 times higher (OR=3.14; 95 % CI: (0.91-5.14); p<0.05), dysmetabolic manifestations (thyroid dysfunction) – 5 times higher (OR=5.11; 95 % CI: (1.61-9.503); p<0.002). Conclusions: Thus, in endometriosis and dyshormonal diseases of the mammary glands, menstrual and generative function disorders, along with clinical symptoms of pelvic pain, dysmenorrhoea, autonomic nervous system disorders and sexual dysfunction, are significant components of this problem, initiating comorbidity processes in target organs in the setting of hormonal maladaptation. Therefore, these comorbidities become a trigger for the activation of systemic hormonal imbalance and become an urgent interdisciplinary problem that requires further study.