From the Research
Thyroid-stimulating hormone (TSH) testing is not routinely indicated in the initial workup for hypertension (HTN) unless there are specific clinical features suggesting thyroid dysfunction.
Clinical Context
When evaluating a patient with hypertension, the primary focus should be on identifying potential secondary causes, including thyroid disorders. However, routine TSH testing for all hypertensive patients is not recommended due to the low prevalence of thyroid disorders as a cause of hypertension, as noted in a study published in the Southern medical journal 1.
Thyroid Disorders and Hypertension
Thyroid disorders can cause secondary hypertension, with hypothyroidism leading to diastolic hypertension due to increased peripheral vascular resistance, and hyperthyroidism typically causing systolic hypertension due to increased cardiac output 2. The association between hypertension and thyroid disorders is well-documented, with studies suggesting that thyroid function tests should be considered in patients with hypertension who exhibit symptoms or signs of thyroid dysfunction 3, 4.
Recommendations
TSH testing should be considered if the patient exhibits symptoms or signs of hypothyroidism (such as fatigue, weight gain, cold intolerance, bradycardia) or hyperthyroidism (such as palpitations, weight loss, heat intolerance, tachycardia). Additionally, if a patient with hypertension has an unusual presentation, is resistant to standard treatments, or develops hypertension at a young age (under 30) or suddenly at an older age, a more comprehensive workup including TSH may be warranted to rule out secondary causes 1. The decision to test TSH should be guided by the clinical context rather than ordered as a routine test for all hypertensive patients.
Key Points
- Routine TSH testing is not recommended for all hypertensive patients
- TSH testing should be considered in patients with symptoms or signs of thyroid dysfunction
- Thyroid disorders can cause secondary hypertension
- Clinical context should guide the decision to test TSH
- Routine testing may not be necessary in the absence of specific clinical features suggesting thyroid dysfunction, as supported by a study published in the British journal of clinical pharmacology 5.