Irregular bleeding refers to vaginal bleeding in women outside of their menstrual period. In a woman’s normal menstrual cycle, vaginal bleeding normally occurs only when she has her period. If there is vaginal bleeding again after her period clears, it is called irregular bleeding. There are various factors that can cause it, including organic lesions of the uterus and endocrine disorders. Organic lesions of the uterus include endometrial polyps and uterine fibroids. Endocrine disorders, in which the body’s hormone levels are not in balance, can also cause symptoms. Therefore, if irregular bleeding is found, it is best to go to the hospital for ultrasound examination.