Blood after menstruation can be caused by cervical polyps, cervicitis, uterine fibroids and other diseases, or endometrial hyperplasia and other diseases. 1. Cervical polyps: the cause of cervical polyps is still unclear, the main symptoms of patients are abnormal vaginal bleeding, leukorrhea, menstrual disorders, etc., which will lead to the phenomenon of blood after menstruation. 2. Cervicitis: Cervicitis is caused by the infection of cervix with pathogens, and the main symptoms of patients are abnormal vaginal bleeding, leukorrhea, vaginal burning, etc., and the symptom of having blood all the time after menstruation. 3. Uterine fibroids: Uterine fibroids are caused by heredity, stem cell dysfunction, etc. Patients will have symptoms such as irregular vaginal bleeding during non-menstrual period, prolonged menstrual period, dysmenorrhea, etc., which leads to the symptom of having blood all the time after menstruation. 4. Other: endometrial hyperplasia, cervical cancer, endometrial polyps and other diseases can also lead to the phenomenon of blood after menstruation. If you have the symptom of blood after menstruation, you should consult a doctor in time and get treatment under the guidance of the doctor.