From the Guidelines
The best first step in the evaluation for secondary hypertension is a thorough clinical history and physical examination, as recommended by the 2024 ESC guidelines for the management of elevated blood pressure and hypertension 1. This should focus on identifying risk factors, symptoms, and signs that suggest specific causes of secondary hypertension. The history should include details about medication use (including over-the-counter drugs, herbal supplements, and illicit substances), family history of hypertension, onset and severity of hypertension, and symptoms suggesting specific etiologies such as headaches, palpitations, or sweating episodes. The physical examination should include proper blood pressure measurements in both arms, assessment for vascular bruits, evaluation of pulses, examination for features of endocrine disorders, and abdominal examination for renal masses or bruits. Basic laboratory tests should follow, including serum electrolytes, creatinine, blood urea nitrogen, urinalysis, and possibly plasma aldosterone and renin levels if primary aldosteronism is suspected, as outlined in the 2020 International Society of Hypertension global hypertension practice guidelines 1. Some key points to consider in the history and physical examination include:
- Medication use, including over-the-counter drugs, herbal supplements, and illicit substances
- Family history of hypertension
- Onset and severity of hypertension
- Symptoms suggesting specific etiologies, such as headaches, palpitations, or sweating episodes
- Proper blood pressure measurements in both arms
- Assessment for vascular bruits
- Evaluation of pulses
- Examination for features of endocrine disorders
- Abdominal examination for renal masses or bruits This comprehensive initial assessment helps determine which patients require further specialized testing for specific causes of secondary hypertension, such as renal artery stenosis, pheochromocytoma, primary aldosteronism, or Cushing's syndrome, as outlined in the 2024 ESC guidelines 1. Secondary hypertension should be particularly suspected in patients with hypertension onset before age 30 or after age 55, sudden worsening of previously controlled hypertension, resistant hypertension, or hypertension with specific clinical features suggesting underlying disorders, as noted in the ACR Appropriateness Criteria for renovascular hypertension 1.
From the Research
Evaluation of Secondary Hypertension
The evaluation of secondary hypertension involves identifying the underlying cause of the condition. According to 2, secondary hypertension occurs in 5% to 10% of all patients with hypertension, and the causes include a range of abnormalities, such as chronic kidney disease and pheochromocytoma.
Initial Steps in Evaluation
The best first step in the evaluation for secondary hypertension is to consider the clinical history, family history, and prevalence of each disease. As stated in 3, nearly all forms of secondary hypertension are related to decreased renal function and/or derangement of hormonal balance or secretion.
Laboratory Tests
Some studies suggest that laboratory tests, such as biochemical assays for blood urea nitrogen and creatinine, can help identify secondary hypertension caused by chronic renal failure. As mentioned in 3 and 4, these tests can provide valuable information about renal function. Additionally, 5 discusses the importance of considering electrolytes, such as potassium and chloride, as well as blood urea nitrogen and creatinine, in the evaluation of renal function.
Key Considerations
Key considerations in the evaluation of secondary hypertension include:
- Clinical history and family history
- Prevalence of each disease
- Laboratory tests, such as blood urea nitrogen and creatinine
- Electrolyte levels, such as potassium and chloride As noted in 6, targeted therapies can be effective in managing secondary hypertension, but the condition is often underrecognized.