What are the typical features of hypertension?

Typical Features of Hypertension

Hypertension is characterized by persistent systolic blood pressure (SBP) ≥130 mm Hg or diastolic BP (DBP) ≥80 mm Hg, affecting approximately 116 million adults in the US and more than 1 billion adults worldwide. 1

Clinical Presentation

• Hypertension is often asymptomatic, which is why it's called the "silent killer" 2
• When symptoms occur, they may include:
  • Headache, particularly in severe or malignant hypertension 3
  • Visual disturbances including blurred vision 3
  • Dizziness 3
  • Chest pain in cases with cardiac involvement 3
  • Dyspnea, especially with hypertensive heart failure 3
  • Neurological symptoms in cases of hypertensive encephalopathy 3

Classification and Diagnostic Thresholds

• Adult hypertension is defined as:

  • SBP ≥130 mm Hg or DBP ≥80 mm Hg 1
  • Stage 1: SBP 140-159 mmHg or DBP 90-99 mmHg 3
  • Stage 2: SBP ≥160 mmHg or DBP ≥100 mmHg 3

• Pediatric hypertension is defined as:

  • BP measurements at or above the 95th percentile for gender, age, and height on 3 or more occasions 3
  • Prehypertension: BP ≥90th percentile but <95th percentile (or ≥120/80 but <95th percentile) 3

Target Organ Damage

Hypertension can affect multiple organs, particularly:

Retina

• Hypertensive retinopathy features include 3:
  • Grade III: Flame-shaped hemorrhages, cotton wool spots
  • Grade IV: All of the above plus papilledema
  • These changes reflect small vessel damage and are highly specific when present bilaterally

Brain

• Hypertensive encephalopathy presents with 3:
  • Headache, visual disturbances
  • Somnolence, lethargy
  • Seizures, cortical blindness
  • Coma in severe cases
• MRI typically shows increased signal intensity on T2-weighted or FLAIR imaging, particularly in posterior brain regions (PRES - Posterior Reversible Encephalopathy Syndrome) 3

Heart

• Left ventricular hypertrophy 4
• Coronary artery disease and myocardial infarction 3
• Cardiogenic pulmonary edema 3
• Heart failure 1

Kidneys

• Acute kidney injury in malignant hypertension 3
• Chronic kidney disease with proteinuria 3
• Thrombotic microangiopathy (TMA) in severe cases 3

Blood Vessels

• Aortic dissection or aneurysm 3
• Peripheral arterial disease 4

Hypertensive Emergencies

Hypertensive emergencies are characterized by severe BP elevation with acute hypertension-mediated organ damage 3:

• Malignant hypertension: Severe BP elevation (usually >200/120 mmHg) with advanced bilateral retinopathy 3
• Hypertensive encephalopathy: Severe hypertension with neurological manifestations 3
• Hypertensive thrombotic microangiopathy: Severe hypertension with hemolysis and thrombocytopenia 3
• Other presentations include severe hypertension with:
  • Cerebral hemorrhage or stroke 3
  • Acute coronary syndrome 3
  • Cardiogenic pulmonary edema 3
  • Aortic dissection 3
  • Severe pre-eclampsia or eclampsia in pregnancy 3

Diagnostic Evaluation

Key diagnostic tests for hypertension evaluation include 3:

• Laboratory analysis:

  • Hemoglobin, platelet count
  • Creatinine, sodium, potassium
  • Lactic dehydrogenase (LDH), haptoglobin (in suspected TMA)
  • Urinalysis for protein and sediment examination

• Diagnostic examinations:

  • ECG (to assess for ischemia, arrhythmias, left ventricular hypertrophy)
  • Fundoscopy (crucial for detecting retinal changes)

• Additional tests as indicated:

  • Cardiac biomarkers (troponin, CK, CK-MB) if cardiac involvement suspected
  • Chest X-ray for fluid overload assessment
  • Echocardiography for cardiac structure and function
  • Brain imaging (CT/MRI) for suspected intracranial hemorrhage
  • CT-angiography for suspected aortic disease
  • Renal ultrasound for kidney assessment

Risk Factors and Etiology

• Secondary causes are found in 20-40% of patients with malignant hypertension 3
• Common secondary causes include:
  • Renal parenchymal disease 3
  • Renal artery stenosis 3
  • Endocrine disorders (less common) 3
• Risk factors for primary hypertension include:
  • Non-modifiable: Age, genetics, ethnicity 2
  • Modifiable: Obesity, high sodium intake, low potassium intake, physical inactivity, alcohol consumption 1

Complications and Pitfalls

• Fewer than half of hypertensive patients are aware of their condition 2
• Only 44% of US adults with hypertension have their BP controlled to <140/90 mmHg 1
• The rate of BP increase appears more important than absolute BP value in developing hypertensive emergencies 3
• Excessive or rapid BP reduction in hypertensive emergencies can lead to organ underperfusion, cerebral infarction, and damage to myocardium and kidneys 3