Postmenopausal bleeding can be due to a number of causes. Examples of some of the most common causes include:
Endometrial atrophy: When the hormone estrogen stops being produced due to menopause, a woman's endometrial lining may start to become thinner. As a result, the lining of the endometrium may be more likely to bleed.
Endometrial hyperplasia: This condition causes the uterine lining to become thicker instead of thinner, giving rise to heavy or irregular bleeding. The cause of this condition is most commonly excess estrogen without the hormone progesterone to offset it. Endometrial hyperplasia can sometimes lead to the development of endometrial cancer.
Endometrial cancer: This is cancer of the endometrial lining. An estimated 10 percent of postmenopausal women with uterine bleeding experience the bleeding due to endometrial cancer.
Polyps: Polyps are growths that can develop on the lining of the uterus. They are usually noncancerous but can cause unusual or heavy bleeding. Polyps can sometimes grow inside the cervical canal. When this occurs, a woman may experience bleeding when she has sex.
Vaginal atrophy (thinning of vaginal tissue): Estrogen helps to keep this tissue healthy. After menopause, low estrogen levels can cause your vaginal walls to become thin, dry, and inflamed. That often leads to bleeding after sex.
Obviously, hysterectomy could get rid of problems associated with uterus, but it can not get rid of bleeding caused by vaginal problems.