Menopause half a year and then come back to the dark brown is considered abnormal, under normal circumstances, after menopause no longer have bleeding, this situation may be senile vaginitis, endometrial cancer, cervical cancer and other causes. Menopause refers to women over 40 years of age, 12 months after the last menstrual period without menstruation, after excluding pregnancy, the clinical can be judged as menopause, menopause half a year and then come back to the brown, considered to be irregular vaginal bleeding. 1. Senile vaginitis: after menopause, estrogen level decreases, vaginal pH increases, resistance decreases, and it is easy to be attacked by external pathogens, and senile vaginitis occurs, and there will be pus and blood vaginal secretion, which is blackish-brown in serious cases. 2. Endometrial cancer: it is a malignant tumor occurring in the epithelium of endometrium, which is related to excessive stimulation of endometrium by estrogen, and mainly manifests as irregular vaginal bleeding or postmenopausal vaginal bleeding. 3. Cervical cancer: it is a malignant tumor of the cervix and is related to the high-risk type of human papillomavirus, i.e., HPV persistent infection, and the patient may manifest as postmenopausal vaginal bleeding. Menopause half a year and come back to the dark brown may also exist other reasons, it is recommended to go to the hospital for a detailed examination, under the guidance of a professional doctor to clarify the cause of the disease, targeted treatment.