Pain Relief During Unsedated Office Hysteroscopy by Applying TENS

Inclusion Criteria: women who attended annual gynecological check up, and were indicated for diagnostic office hysteroscopy because of different pathologies such as: * postmenopausal endometrial thickening \>4mm; * postmenopausal abnormal uterine bleeding; * suspicious endometrial polyp or leiomyoma; * infertility study; * suspicious endometrial carcinoma; * hypermenorrhea Exclusion Criteria: * age less than 18; * previous cervical surgery; * neurological deficit; * chronic or preprocedural use of opioids or psychoactive drugs; * previous experience in TENS; * cutaneous damage on the application sites; * pacemakers or automatic implanted cardiac defibrillators; * refusal to sign the informed consent form; * inability to understand informed consent form.