Patients should not take hormone replacement therapy (HRT) drugs if they have been diagnosed with or experienced any of the following conditions:

• Pregnancy
• Vaginal bleeding
• Stroke or heart attack in past year
• Blood clots
• Liver disease
• Some forms of cancer, including those of the breast, endometrium and uterus

Women with noncancerous (benign) tumors of the uterus (uterine fibroids) may find that HRT makes the fibroids grow larger, but this is not typical. In addition, HRT has been linked with increased breast density in some women undergoing the therapy making it more difficult to read mammograms.