What is the ruling on menstruation occurring twice a month, with the period of purity between them being less than fifteen days, and each menstruation lasting from ten to twelve days, and is the bleeding considered menses if its symptoms and characteristics match those of menstrual blood, despite a hormonal imbalance?

The general rule for blood exiting the uterus without childbirth is that it is menstrual blood (hayd). If the blood reappears after it has stopped and after the woman's usual cycle, it could be hayd or istihada (non-menstrual vaginal bleeding). If the period between the cessation of the previous bleeding and the new bleeding is thirteen days (according to the Hanbalis), then it is a second hayd. However, if it is less than that, it cannot be considered a new hayd because the duration does not reach the minimum purity period between two menstrual cycles, nor is it a continuation of the previous hayd. Therefore, it is considered istihada by the Hanbalis and the majority of scholars.