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 1. The most recent and highest quality study, the 2020 international society of hypertension global hypertension practice guidelines, highlights the importance of early diagnosis and targeted treatment of secondary hypertension to potentially cure hypertension or improve blood pressure control 1.
Common Causes of Secondary Hypertension
- Renal parenchymal disease: 1%–2% prevalence, associated with urinary tract infections, obstruction, hematuria, and analgesic abuse 1
- Renovascular disease: 5%–34% prevalence, associated with resistant hypertension, abrupt onset or worsening of hypertension, and flash pulmonary edema 1
- Primary aldosteronism: 8%–20% prevalence, associated with resistant hypertension, hypokalemia, and muscle cramps or weakness 1
- Chronic sleep apnea: 25%–50% prevalence, associated with resistant hypertension, snoring, fitful sleep, and daytime sleepiness 1
- Substance/drug-induced hypertension: 2%–4% prevalence, associated with sodium-containing antacids, caffeine, nicotine, alcohol, and certain medications 1
Diagnosis and Treatment
Diagnosis of secondary hypertension typically involves a thorough medical history, physical examination, laboratory tests, and sometimes imaging studies 1. Treatment should focus on addressing the underlying condition while managing blood pressure with appropriate medications 1. It is essential to suspect secondary hypertension in patients with resistant hypertension, sudden onset of hypertension, or hypertension developing at a young age or without family history 1.
From the FDA Drug Label
The study population was diverse with regard to race (Asian 16.7%, Black 15.2%, Hispanic 18. 3%, White 48.6%). Overall, 63.2% of the patients were men, and 66.4% were under the age of 65 years. Almost all of the patients (96.6%) had a history of hypertension, The FDA drug label does not answer the question.
From the Research
Secondary Causes of Hypertension
The secondary causes of hypertension are identifiable and potentially correctable conditions or diseases that lead to high blood pressure. Some of the common secondary causes of hypertension include:
- Renovascular disease
- Renal parenchymal disease
- Primary hyperaldosteronism
- Drug and substance use
- Obstructive sleep apnea Less common etiologies include:
- Pheochromocytoma/paraganglioma
- Cushing syndrome
- Thyroid and parathyroid conditions
- Congenital adrenal hyperplasia
- Aortic coarctation 2, 3
Prevalence of Secondary Hypertension
It is estimated that 5-10% of hypertensive patients have secondary hypertension 4, 3. The identification of these patients is crucial as it enables the etiological management of the underlying disease, which can lead to blood pressure control without antihypertensive medications in some cases 4.
Diagnosis and Management
The diagnosis of secondary hypertension often involves complex and expensive tests, and should only be performed in patients with a strong clinical suspicion for its presence 4. The management of secondary hypertension involves treating the underlying condition, and some patients may benefit from referral to a specialist with specific expertise in treating the causative condition 2, 5.
Clinical Features and Diagnostic Options
Selection of patients for testing should incorporate historical and clinical clues, previous treatment course, and comorbidities 5. Secondary hypertension should be considered in the presence of suggestive symptoms and signs, such as severe or resistant hypertension, age of onset younger than 30 years, malignant or accelerated hypertension, and an acute rise in blood pressure from previously stable readings 3.