Final answer:
Unexplained vaginal bleeding is an absolute contraindication to post-menopausal hormone therapy because it can indicate a serious underlying condition that could be worsened by hormone therapy. Other contraindications include history of blood clots and certain cancers.
Step-by-step explanation:
The student asks which of the following is an absolute contraindication to post-menopausal hormone therapy: unexplained vaginal bleeding, seizure disorder, endometriosis, or cigarette smoking. An absolute contraindication means a situation where a medication should not be used because it may be harmful. The correct answer is unexplained vaginal bleeding, as it could indicate an underlying disorder that could be exacerbated by hormone therapy. Conditions such as a history of blood clots, breast, liver, or endometrial cancer are also contraindications. Hormone replacement therapy (HRT) has side effects, including an increased risk of stroke or heart attack, blood clots, and various cancers, which is why its use is approached with caution.