Hormone therapy is a powerful medical tool used to manage a wide range of conditions, from menopausal symptoms and contraception to gender affirmation. However, because hormones regulate fundamental bodily functions, they carry specific risks and are not appropriate for everyone. A person's medical history, current health status, and specific hormone regimen all play critical roles in determining the safety and suitability of treatment. Healthcare providers consider a variety of absolute and relative contraindications before prescribing any form of hormone medication.
Absolute Contraindications for Hormone Therapy
Absolute contraindications are conditions that generally prevent a person from safely using hormone therapy due to a high risk of serious adverse events. These are often non-negotiable and require a doctor to explore alternative treatments.
History of Certain Cancers
Hormone-sensitive cancers are a primary concern, as hormones can stimulate the growth of certain cancer cells. A history of breast cancer is a major contraindication for estrogen therapy and combined hormone replacement therapy (HRT). Known or suspected estrogen-dependent cancer of the uterus or ovaries is also a contraindication. For individuals assigned male at birth, a history of prostate cancer, especially locally advanced or metastatic, is a contraindication for testosterone therapy.
Cardiovascular and Thromboembolic Risks
Many hormone therapies can increase the risk of blood clots, heart attack, and stroke. A history of deep venous thrombosis (DVT) or pulmonary embolism (PE) is a strong contraindication for most estrogen-containing therapies and combined hormonal contraceptives. Those with a recent history of stroke or heart attack are typically advised against hormone therapy. Poorly controlled high blood pressure also increases cardiovascular risk and can be a contraindication for combined hormonal contraceptives and HRT.
Liver Disease
Active or severe liver disease with abnormal function tests is a contraindication for many systemic hormone treatments, as the liver is crucial for processing hormones.
Other Specific Conditions
Undiagnosed vaginal bleeding requires investigation before starting HRT. Hormone therapy is also generally contraindicated during pregnancy.
Relative Contraindications and Cautionary Factors
For some individuals, hormone therapy requires extra caution, monitoring, or a different regimen, with the doctor carefully weighing risks versus benefits. Starting HRT after age 60, especially more than 10 years after menopause, is associated with a higher risk of cardiovascular events, stroke, and dementia. Women with migraines with aura should avoid estrogen-containing contraceptives due to increased stroke risk. Smoking, particularly in women over 35, dramatically increases the risk of cardiovascular events with combined hormonal contraception. Obesity is an independent risk factor for blood clots and cardiovascular disease and can complicate hormone therapy. Uncontrolled diabetes with vascular complications can increase risks with combined hormonal contraception. Untreated severe obstructive sleep apnea is a cautionary factor for testosterone therapy.
Hormone Type-Specific Considerations
Different hormone therapies have distinct risk profiles.
Combined Estrogen and Progestin Therapy
Contraindicated with a history of breast or endometrial cancer, blood clots, stroke, heart attack, or uncontrolled hypertension. Risks include increased risk of blood clots, stroke, and breast cancer with long-term combined use. For women with a uterus, estrogen must be combined with progestin to prevent endometrial cancer.
Estrogen-Only Therapy (for women without a uterus)
Contraindicated with a history of estrogen-sensitive cancers or blood clots. Risks include increased risk of stroke, blood clots (oral route), and gallbladder disease.
Testosterone Therapy (for men)
Contraindicated with prostate cancer, male breast cancer, uncontrolled heart failure, or elevated hematocrit. Can cause infertility.
Hormonal Contraceptives
Combined (estrogen and progestin) are avoided in women over 35 who smoke, those with a history of blood clots, stroke, breast cancer, or migraines with aura. Progestin-only is often safer for those with estrogen contraindications.
Comparison of Contraindications for Different Hormone Therapies
| Condition | Menopausal HRT (Estrogen ± Progestin) | Combined Hormonal Contraceptives | Testosterone Therapy |
|---|---|---|---|
| Active Cancer | Contraindicated for hormone-sensitive types (breast, endometrial). | Contraindicated for hormone-sensitive types (breast). | Contraindicated for prostate or male breast cancer. |
| History of Blood Clots | Contraindicated (especially oral forms). | Contraindicated. | Can increase hematocrit, which raises clot risk. |
| Active Liver Disease | Contraindicated. | Contraindicated for certain liver conditions. | Requires careful monitoring or is contraindicated. |
| Uncontrolled Hypertension | Relative contraindication; increased risk of stroke. | Contraindicated. | Requires careful monitoring; some risk. |
| Migraine with Aura | Varies by dose and route; transdermal may be safer. | Contraindicated. | Generally not a contraindication. |
| Smoking (age > 35) | Relative contraindication; increases cardiovascular risk. | Contraindicated. | No direct contradiction, but worsens cardiovascular risks. |
| Pregnancy | Contraindicated. | Contraindicated. | Contraindicated (risk of fetal harm). |
The Importance of Personalized Medical Evaluation
An informed decision about hormone therapy is personalized and requires close collaboration with a healthcare provider. A thorough medical evaluation, including a review of medical history, is standard. Diagnostic tests such as mammograms and blood work may be performed. Patients should understand all potential risks, benefits, and alternatives. For many conditions that make hormone use risky, safer alternatives exist, such as certain antidepressants for hot flashes, or progestin-only options for contraception.
Conclusion
Hormones can be crucial for managing various health issues but are not universally safe. Individuals with a history of hormone-sensitive cancers, blood clotting disorders, active liver disease, or certain cardiovascular conditions should generally avoid them. Factors like age, smoking status, and specific medical histories also play a significant role. The decision to use hormones should always follow a careful, personalized medical evaluation to weigh benefits against potential complications. Consulting a qualified healthcare professional is vital to assess individual circumstances and recommend the safest plan, which may include non-hormonal alternatives.
