What causes hypertension?

Causes of High Blood Pressure (Hypertension)

High blood pressure is caused by a combination of primary (essential) hypertension with unknown exact causes in approximately 90% of patients and secondary hypertension with identifiable causes in about 10% of patients, with multiple risk factors including obesity, excess sodium intake, insufficient physical activity, and genetic predisposition. 1

Primary vs. Secondary Hypertension

Primary (Essential) Hypertension

• Accounts for approximately 90% of all hypertension cases 1
• Exact cause remains unknown but involves multiple factors:
  • Genetic predisposition (more than 25 rare mutations and 120 single-nucleotide polymorphisms identified) 1
  • Environmental factors
  • Lifestyle factors
  • Physiological mechanisms

Secondary Hypertension

• Accounts for approximately 10% of hypertension cases 1
• Has identifiable underlying causes:
  • Endocrine disorders:
    • Primary aldosteronism
    • Pheochromocytoma
    • Cushing's syndrome
    • Hyperparathyroidism 1
  • Renal causes:
    • Renal parenchymal disease (chronic glomerulonephritis, polycystic kidney disease)
    • Renovascular disease 1
  • Genetic syndromes:
    • Liddle's syndrome
    • Glucocorticoid-remediable aldosteronism 1
  • Other causes:
    • Obstructive sleep apnea
    • Coarctation of the aorta
    • Drug-induced hypertension 1

Modifiable Risk Factors

Obesity and Body Composition

• Central obesity (measured by waist-to-hip ratio) has a stronger relationship with blood pressure than BMI 1
• Weight reduction to normal BMI is recommended for hypertension prevention 1

Dietary Factors

• Excessive sodium consumption directly linked to blood pressure increases
• Salt sensitivity more common in Black individuals, older adults, and those with comorbidities 1
• The DASH diet (rich in fruits, vegetables, whole grains, and low-fat dairy) is recommended for hypertension management 1

Physical Activity

• Insufficient physical activity contributes to hypertension risk 1
• Regular physical activity (150+ minutes/week) is recommended for prevention and management 1

Medications and Substances

• Over-the-counter medications, prescribed drugs, and recreational substances can cause hypertension:
  • Anticancer drugs
  • Tyrosine kinase inhibitors
  • Proteasome inhibitors
  • Corticosteroids
  • NSAIDs
  • Anti-androgen therapy 1

Other Lifestyle Factors

• Excessive alcohol consumption
• Chronic stress
• Poor sleep quality
• Obstructive sleep apnea 1

Non-Modifiable Risk Factors

Genetic Factors

• Strong genetic component with more than 25 rare mutations and 120 single-nucleotide polymorphisms identified 1
• Family history of hypertension increases risk

Emerging Risk Factors

• Gut microbiota alterations 1
• Environmental stressors

Pathophysiological Mechanisms

Hypertension often develops through multiple interacting mechanisms:

• Sympathetic nervous system overactivity
• Renin-angiotensin-aldosterone system dysregulation
• Endothelial dysfunction
• Vascular remodeling
• Altered sodium handling by kidneys

Common Pitfalls in Hypertension Management

• Overlooking secondary causes: Always consider secondary hypertension in resistant cases (blood pressure that remains above goal despite using ≥3 antihypertensive medications at optimal doses, including a diuretic) 1
• Improper blood pressure measurement: Can lead to misdiagnosis or improper treatment 1
• Medication nonadherence: A common cause of resistant hypertension 1
• Ignoring lifestyle factors: These can significantly impact blood pressure control 1
• Missing drug-induced causes: Many medications can cause or worsen hypertension 1

Understanding the complex interplay of factors causing hypertension is essential for effective prevention and management strategies that can reduce the risk of hypertension-mediated organ damage affecting the heart, brain, kidneys, and blood vessels 1.