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title: Hypertension created: 2025-01-17 updated: 2025-01-17 tags: [#medical/cardiology, #clinical/chronic-disease, #exam/high-yield] aliases: [HTN, High Blood Pressure, Essential Hypertension, Primary Hypertension] evidence_level: A source: ACC/AHA Hypertension Guidelines 2023

Hypertension

Quick Reference

[!tip] Clinical Pearl Remember the 2017 ACC/AHA guidelines: Stage 1 HTN = 130-139/80-89, Stage 2 HTN ≥140/90. Treatment threshold depends on ASCVD risk!

Overview

Definition: Sustained elevation of systemic arterial blood pressure - Stage 1: SBP 130-139 or DBP 80-89 mmHg - Stage 2: SBP ≥140 or DBP ≥90 mmHg

ICD-10: I10 (Essential hypertension) Prevalence: ~47% of US adults (116 million people)

Etiology & Risk Factors

Primary Hypertension (90-95%)

Non-modifiable - Age (risk increases >55 men, >65 women) - Family history - Race (higher in African Americans) - Genetic factors

Modifiable - Obesity (BMI >30) - High sodium intake (>2.3g/day) - Physical inactivity - Excessive alcohol (>2 drinks/day men, >1 women) - Stress - Sleep apnea

Secondary Hypertension (5-10%)

  • Renal: CKD, renovascular disease, PKD
  • Endocrine: Primary aldosteronism, Cushing's, pheo, thyroid
  • Vascular: Coarctation, vasculitis
  • Medications: NSAIDs, OCPs, steroids, decongestants
  • Other: OSA, pregnancy (preeclampsia)

Pathophysiology

graph TD
    A[Increased Peripheral Resistance] --> B[Hypertension]
    C[Increased Cardiac Output] --> B
    D[Sodium Retention] --> C
    E[RAAS Activation] --> A
    F[Sympathetic Activation] --> A
    F --> C
    G[Endothelial Dysfunction] --> A

Clinical Features

History

  • Usually asymptomatic ("silent killer")
  • When symptomatic:
  • Headaches (severe HTN)
  • Epistaxis
  • Dizziness
  • Visual changes
  • Screen for target organ damage symptoms

Physical Examination

  • Vital Signs: BP in both arms, orthostatics if indicated
  • Fundoscopy: Hypertensive retinopathy (AV nicking, copper wire)
  • Cardiac: S4 gallop, LVH (displaced PMI)
  • Vascular: Carotid bruits, diminished pulses, abdominal bruits
  • Neuro: Focal deficits suggesting prior CVA

BP Measurement Technique

  1. Patient seated 5 minutes, back supported
  2. Arm at heart level
  3. Proper cuff size (bladder encircles 80% arm)
  4. Average of ≥2 readings on ≥2 occasions

Investigations

Initial Workup

  1. Basic labs
  2. BMP (creatinine, K+)
  3. Lipid panel
  4. HbA1c or FBS
  5. Urinalysis (proteinuria)
  6. ECG (LVH, prior MI)

If Secondary HTN Suspected

  • 24-hour urine metanephrines (pheo)
  • Aldosterone:renin ratio (primary aldo)
  • Renal artery imaging (renovascular)
  • Sleep study (OSA)
  • TSH (thyroid disease)

Target Organ Assessment

  • Echo (if LVH suspected)
  • Urine albumin:creatinine ratio
  • Fundoscopy
  • Ankle-brachial index (PAD)

Management

Lifestyle Modifications (All Patients)

Intervention SBP Reduction
Weight loss (10 kg) 5-20 mmHg
DASH diet 8-14 mmHg
Sodium restriction (<2.3g/day) 2-8 mmHg
Physical activity (150 min/week) 4-9 mmHg
Alcohol moderation 2-4 mmHg

Pharmacologic Treatment

Initiation Thresholds: - Stage 1 + ASCVD or 10-year risk ≥10%: Start meds - Stage 1 + 10-year risk <10%: Lifestyle first - Stage 2: Start meds regardless of risk

First-Line Agents: | Drug Class | Examples | Key Points | |------------|----------|------------| | ACE inhibitors | Lisinopril 10-40mg | Cough, hyperkalemia, ↑Cr | | ARBs | Losartan 50-100mg | If ACE cough | | Thiazides | HCTZ 25mg, Chlorthalidone 12.5-25mg | Hypokalemia, ↑glucose | | CCBs | Amlodipine 5-10mg | Peripheral edema |

Special Populations: - African Americans: Thiazide or CCB first - CKD + proteinuria: ACE/ARB first - Post-MI/HF: Beta-blocker + ACE/ARB - Pregnancy: Methyldopa, labetalol, nifedipine

Treatment Algorithm

graph TD
    A[Stage 1 or 2 HTN] --> B{ASCVD or Risk ≥10%?}
    B -->|Yes| C[Start single agent]
    B -->|No + Stage 1| D[Lifestyle 3-6 months]
    B -->|No + Stage 2| C
    C --> E{At goal?}
    E -->|No| F[Increase dose or add 2nd agent]
    F --> G{At goal?}
    G -->|No| H[Add 3rd agent]
    H --> I[Consider secondary causes]

Complications

Cardiovascular

  • CAD, MI
  • Heart failure (HFpEF > HFrEF)
  • Atrial fibrillation
  • Aortic dissection

Cerebrovascular

  • Ischemic stroke
  • Hemorrhagic stroke
  • Vascular dementia

Renal

  • Hypertensive nephrosclerosis
  • CKD progression
  • Acute kidney injury (malignant HTN)

Other

  • Hypertensive retinopathy → blindness
  • Peripheral arterial disease
  • Sexual dysfunction

Special Situations

Hypertensive Urgency

  • BP >180/120 without acute organ damage
  • Lower BP gradually over 24-48 hours
  • PO meds: Clonidine, labetalol, captopril

Hypertensive Emergency

  • BP >180/120 WITH acute organ damage
  • IV therapy, ICU monitoring
  • Lower MAP by 10-20% in first hour
  • Agents: Nicardipine, labetalol, nitroprusside

Resistant Hypertension

  • Uncontrolled despite ≥3 drugs (including diuretic)
  • Confirm adherence, proper technique
  • Screen for secondary causes
  • Consider spironolactone as 4th agent

Prognosis

  • Well-controlled HTN: Near-normal life expectancy
  • Each 20/10 mmHg increase doubles CV risk
  • Treatment reduces stroke by 35-40%, MI by 20-25%, HF by 50%

Key Points for Exams 🎯

  • Know BP classification: Stage 1 (130-139/80-89), Stage 2 (≥140/90)
  • First-line drugs: ACE/ARB, thiazide, CCB (NOT beta-blockers unless compelling indication)
  • Special populations: African Americans (thiazide/CCB), CKD (ACE/ARB), pregnancy (avoid ACE/ARB)
  • Secondary HTN screening: Young (<30), severe/sudden onset, resistant HTN
  • Lifestyle modifications: DASH diet most effective (8-14 mmHg reduction)
  • Hypertensive emergency vs urgency: Presence of acute organ damage

References