Abnormal uterine bleeding is irregular bleeding from the uterus. It may be caused by accidental factors and may resolve itself when the cause is removed. If it is caused by organic diseases, the bleeding usually cannot be stopped by itself. 1. Accidental factors: There are many causes of abnormal uterine bleeding, such as taking hormonal drugs, stress, and transient disorders of ovarian function, all of which may lead to abnormal uterine bleeding. By removing the causes, the bleeding may stop by itself. 2. Organic diseases: uterine and ovarian organic lesions, such as endometrial polyps, uterine smooth muscle tumors, uterine adenomyosis, endometrial cancer caused by abnormal uterine bleeding. If the disease is left untreated and the lesion persists, the bleeding usually does not stop on its own. Abnormal uterine bleeding can be observed closely if it occurs occasionally. If the bleeding persists, it is recommended to go to the hospital for examination and treatment in time to avoid serious harm.