Any woman who begins bleeding after menopause should see a doctor, wrote EverydayHealth.com. WebMD said that even a little spotting is not normal after menopause.
Natural menopause is confirmed after 12 consecutive months without a period, said the Mayo Clinic.
Dr. Oz wrote that bleeding that originates from the cervix can occur if there is a benign cervical polyp or cervical inflammation. Cervical and vaginal cancers can also cause bleeding, but are less common.
Abnormal bleeding from the uterine cavity is caused by hormonal imbalances, benign growths such as polyps or fibroids, pre-cancer or cancer, said Dr. Oz.
Mayo Clinic reported that uterine polyps need to be removed, because in rare cases they can be a potential site of cancerous growths.
Fibroids (benign growths in the uterus) tend to shrink after menopause and typically don't require treatment. However fibroids that grow and are associated with postmenopausal bleeding need to be removed because of potential malignant changes.
A frequent cause of postmenopausal bleeding is endometrial atrophy (the thinning of the tissues that line the uterus).
WebMD wrote that the endometrium can become very thin after menopause because of diminished estrogen levels, and may cause unexpected bleeding. Endometrial atrophy can be treated with medication.
WebMD said another cause could be endometrial hyperplasia. The lining of the uterus becomes thick, usually as a result of too much estrogen and too little progesterone, and bleeding may occur as a result.
Endometrial hyperplasia may be treated with medication and/or surgery to remove thickened endometrium areas.
Endometrial hyperplasia should be treated as soon as possible, advised the Mayo Clinic. Women with this condition have an increased risk for developing endometrial cancer (uterine cancer).
Other causes could be cervical or uterine infections and use of certain medications such as blood thinners, wrote WebMD. WomentoWomen.com said that hormonal changes or rebalancing is another reason for postmenopausal bleeding.
Postmenopausal bleeding is unfortunately also a sign of endometrial cancer, wrote WebMD.