From the Guidelines
Secondary hypertension is most commonly caused by renal parenchymal disease, renovascular hypertension, primary aldosteronism, chronic sleep apnea, and substance/drug-induced hypertension, as identified in 5%–10% of hypertensive patients. The diagnosis of secondary hypertension involves a thorough medical history, physical examination, and targeted testing based on suspected causes, such as blood and urine tests, imaging studies, or sleep studies 1.
Common Causes of Secondary Hypertension
- Renal parenchymal disease
- Renovascular hypertension
- Primary aldosteronism
- Chronic sleep apnea
- Substance/drug-induced hypertension Treatment primarily focuses on addressing the underlying condition rather than just managing blood pressure, with the potential to cure hypertension in some patients or improve BP control/reduce the number of prescribed antihypertensive medications in others 1.
Diagnosis and Treatment Approach
- A thorough medical history and physical examination are essential for identifying potential causes
- Targeted testing, such as blood and urine tests, imaging studies, or sleep studies, is guided by suspected causes
- Treatment aims to address the underlying condition, which may involve removing an adrenal tumor, treating kidney disease, or discontinuing problematic medications
- Temporary use of blood pressure medications may be necessary while addressing the underlying cause, with choices depending on the specific cause and patient characteristics 1.
From the Research
Causes of Secondary Hypertension
The causes of secondary hypertension are varied and can be attributed to several underlying conditions. Some of the main causes include:
- Renal parenchymal disease 2, 3, 4
- Renovascular diseases, such as atherosclerotic renal artery stenosis 2, 3, 4, 5, 6
- Coarctation of the aorta 2, 4
- Cushing's syndrome 2, 4, 5
- Primary hyperaldosteronism 2, 3, 4, 5
- Pheochromocytoma 2, 4, 5
- Hyperthyroidism 2, 4
- Hyperparathyroidism 2, 4
- Obstructive sleep apnea 4, 5, 6
- Drug-induced hypertension 5, 6
Identification of Secondary Hypertension
The identification of secondary hypertension is crucial, as it enables the etiological management of the underlying disease and can lead to blood pressure control without antihypertensive medications 3. The diagnosis of secondary hypertension can be aided by:
- Onset of hypertension before the age of 20 or after the age of 50 years 2
- Markedly elevated blood pressure or hypertension with severe end-organ damage 2
- Specific body habitus and ancillary physical findings, such as truncal obesity and purple striae in Cushing's syndrome 2
- Resistant or refractory hypertension 2, 4
- Specific biochemical tests, such as hypercalcemia in hyperparathyroidism 2
- Abdominal diastolic bruits, decreased femoral pulses, or bitemporal hemianopias 2
Evaluation and Management
The evaluation and management of secondary hypertension often require a combination of clinical suspicion, laboratory tests, and imaging studies 2, 3, 4, 5, 6. The goal of evaluation is to identify the underlying cause of hypertension and to provide targeted therapy to supplement first-line antihypertensive agents 5. Early detection and treatment are important to minimize or prevent irreversible changes in the vasculature and target organs 6.