From the Guidelines
Thyroid-stimulating hormone (TSH) testing is not routinely indicated for the initial investigation of hypertension (HTN) in most patients. The standard workup for hypertension typically includes a comprehensive history, physical examination, basic metabolic panel, complete blood count, urinalysis, and electrocardiogram, as recommended by the 2024 ESC guidelines for the management of elevated blood pressure and hypertension 1. TSH testing should be considered selectively when there are clinical features suggesting thyroid dysfunction, such as unexplained tachycardia or bradycardia, weight changes, heat or cold intolerance, or physical findings like goiter or exophthalmos.
Key Considerations
- Thyroid disorders, particularly hyperthyroidism and hypothyroidism, can cause secondary hypertension, but they are relatively uncommon causes.
- Hyperthyroidism may present with systolic hypertension due to increased cardiac output and reduced peripheral resistance, while hypothyroidism can lead to diastolic hypertension through increased peripheral vascular resistance.
- In patients with resistant hypertension (blood pressure remaining above goal despite three appropriate antihypertensive medications) or hypertension presenting at a young age (under 30), a more comprehensive evaluation for secondary causes including thyroid function may be warranted, as suggested by the 2020 International Society of Hypertension global hypertension practice guidelines 1.
Evidence-Based Recommendations
- The 2020 U.S. Department of Veterans Affairs/U.S. Department of Defense clinical practice guideline also emphasizes the importance of routine screening for hypertension, but does not recommend routine TSH testing for all hypertensive patients 1.
- A targeted approach to TSH testing, based on clinical features and risk factors, is more cost-effective than universal screening in all hypertensive patients.
- The 2024 ESC guidelines prioritize the measurement of serum creatinine, eGFR, and urine ACR in all patients with hypertension, as well as a 12-lead ECG, but do not recommend routine TSH testing 1.
From the Research
Thyroid-Stimulating Hormone (TSH) and Hypertension (HTN)
- TSH is not typically indicated for routine investigation of hypertension, as secondary hypertension due to thyroid disease is relatively rare, representing around 1% of all hypertension cases 2, 3.
- However, thyroid disorders can cause significant changes in blood pressure, and identifying these conditions can lead to specific treatments and improved blood pressure control 2, 4.
- Certain patient populations, such as those with resistant hypertension, may benefit from TSH screening, as thyroid disease can be a reversible cause of hypertension 5.
- Studies have shown that thyroid disease is often under-screened in patients with hypertension, particularly in those with resistant hypertension 5.
- The association between hyperthyroidism and hypertension is well-established, with hyperthyroidism causing increased cardiac output, systolic blood pressure, and levels of renin, angiotensin, and aldosterone 3, 4.
- Clinicians should consider the possibility of hyperthyroidism in patients with hypertension, even in older patients, as treatment of hyperthyroidism can potentially cure hypertension in some cases 3, 4.