The term “vacation” is generally used to refer to menstruation in women. The characteristics of menstruation in a twin uterus may include heavy menstrual flow, prolonged menstrual period or menstrual cramps. 1. Heavy menstrual flow: Due to the presence of two uterine lining in a twin uterus, under the influence of hormone levels, both lining develops and sheds at the same time to form menstruation, which may result in heavier menstrual flow. 2. Prolonged menstrual period: As the two endometriums of a twin uterus do not shed their lining at the same time during menstruation, prolonged menstrual period may result. 3. Dysmenorrhea: Duplex uterus is prone to dysplasia of one side of the uterus or narrow cervical canal, etc., which may cause dysmenorrhea during menstruation. Duplex uterus is a congenital developmental abnormality, and the main reason is considered to be related to heredity. If you have a double uterus, you need to go to the hospital for treatment if you feel unwell.