This is the most common cause of post-menopausal bleeding (PMB). About three-quarters (75%) of women with PMB will have atrophic vaginitis. See more about bleeding after sex. Atrophy refers to the thinning of tissues (as a result of less oestrogen) which can affect your vagina, the lining of your uterus (endometrium) and your urinary tract.
Endometrial hyperplasia and endometrial cancer
About 10% of women with PMB will have endometrial hyperplasia and another 10% will have endometrial cancer. Endometrial hyperplasia is when the lining of your uterus gets thicker and causes heavy or abnormal bleeding – particularly around the time of menopause or afterwards. While it isn't cancerous itself, it may increase your risk of developing endometrial cancer if it's not treated. Early diagnosis and treatment of endometrial cancer is very successful.
Cervical or endometrial polyps
Polyps are areas of abnormal growth of the lining of the uterus that stick out from the normal lining. They're not usually cancerous, but endometrial polyps can become cancerous. They can also make it difficult to know if there is cancer present in the endometrium – because they can make the endometrium look thick and abnormal on an ultrasound scan.
Menopausal hormone therapy
Menopausal hormone therapy (previously called hormone replacement therapy or HRT) can treat some of the symptoms of menopause with oestrogen. To do this safely, it's necessary to combine oestrogen and progesterone to mimic your monthly cycles and prevent the lining of your uterus growing too thick. However, by adding in progesterone, you will continue to have vaginal bleeding similar to a period.
Tamoxifen is a medicine used to treat breast cancer. In breast tissue, tamoxifen protects against the effect of oestrogen but, in the uterus, tamoxifen acts like oestrogen. For this reason, women taking tamoxifen are more at risk of developing endometrial cancer. If you're using tamoxifen and you have any abnormal vaginal bleeding, you need to see your healthcare provider immediately.
Post-menopausal bleeding can also be due to cervical cancer, but this is rare.
If you have an underlying bleeding problem (eg, if you take too much anticoagulant medicine), you may have vaginal bleeding. If that's the case you'll usually have bleeding from other places as well – especially from your nose, or from your gums when you brush your teeth.