Hypertension (High Blood Pressure)
A) Condition Overview
Hypertension is persistently elevated blood pressure in the arteries, commonly called "high blood pressure." It is the leading modifiable risk factor for cardiovascular disease, stroke, heart failure, kidney disease, and premature death globally 1. Most cases are asymptomatic, earning it the nickname "the silent killer" 1.
1. Enabling Conditions, Epidemiology, and Risk Factors
Epidemiology
- Affects approximately 116 million adults in the United States and over 1 billion adults worldwide 2
- Prevalence increases dramatically with age, affecting 75% of people over age 70 3
- Only 44% of US adults with hypertension have their blood pressure controlled to <140/90 mm Hg, with control rates declining from 53.8% in 2013-14 to 43.7% in 2017-18 1, 2
- African Americans develop hypertension at younger ages and present with higher rates of complications including stroke and end-stage kidney disease 1
Risk Factors
- Age >65 years, male sex, increased body weight/obesity 1
- Family history of hypertension or cardiovascular disease 1
- Diabetes mellitus, dyslipidemia (high LDL cholesterol/triglycerides) 1
- Smoking, excessive alcohol consumption 1
- High sodium intake, low potassium intake 2
- Physical inactivity, psychosocial/socioeconomic stressors 1
- Environmental exposures: uranium-contaminated drinking water (increases BP by 7.4/5.0 mm Hg per 1 mg/L) 4
- Early-onset menopause in women 1
Secondary Hypertension (5-10% of cases)
- Renal parenchymal disease, renovascular hypertension 1
- Primary aldosteronism, chronic sleep apnea 1
- Drug/substance-induced (NSAIDs, steroids, stimulants) 1
- Thyroid disorders, Cushing's syndrome 1
2. Pathophysiology and Mechanism
Primary Mechanisms
Hypertension involves complex dysregulation of multiple organ systems including the kidneys, cardiovascular system, and central nervous system, along with hormonal networks (renin-angiotensin-aldosterone system), vascular mechanisms, and immune processes 1.
Key Pathophysiologic Components
- Increased peripheral vascular resistance due to endothelial dysfunction, vasoreactivity changes, and vascular remodeling 1
- Sodium and water retention by the kidneys 1
- Sympathetic nervous system overactivity 1
- Renin-angiotensin-aldosterone system activation 1
- Arterial stiffening and loss of compliance 1
Symptom Cascade and Organ Damage
Persistently elevated blood pressure leads to hypertension-mediated organ damage (HMOD) through structural and functional changes in target organs 1:
- Heart: Left ventricular hypertrophy (LVH), left atrial dilatation, diastolic dysfunction, eventual heart failure, coronary artery disease 1
- Brain: White matter lesions, silent microinfarcts, microbleeds, brain atrophy, increased stroke risk 1
- Kidneys: Glomerular damage, proteinuria/albuminuria, declining eGFR, progression to chronic kidney disease and end-stage renal disease 1
- Arteries: Atherosclerotic plaque formation, arterial stiffening (increased pulse wave velocity), carotid intima-media thickening 1
- Eyes: Retinopathy with arteriovenous nicking, hemorrhages, exudates 1
Interaction with Comorbidities
- Diabetes amplifies cardiovascular risk and accelerates kidney damage; requires more aggressive BP targets <130/80 mm Hg 1
- Chronic kidney disease is both a cause and consequence of hypertension, creating a vicious cycle 1
- Hyperlipidemia synergistically increases atherosclerosis risk beyond hypertension alone 1
3. Clinical Presentation and Diagnosis
Key Symptoms
Hypertension is typically asymptomatic until complications develop 1. When symptoms occur, they may include:
- Headaches (particularly occipital, morning headaches) 3
- Dizziness, lightheadedness 3
- Blurred vision 3
- Chest pain (if coronary disease present) 3
- Shortness of breath (if heart failure present) 3
Red Flags (Hypertensive Emergency)
Blood pressure >180/120 mm Hg with end-organ dysfunction requires immediate treatment 3:
- Severe headache, confusion, altered mental status (hypertensive encephalopathy) 3
- Chest pain, acute coronary syndrome 3
- Acute shortness of breath, pulmonary edema 3
- Focal neurologic deficits, stroke symptoms 3
- Visual changes, papilledema 3
Physical Exam Findings
- Elevated blood pressure on repeated measurements (proper technique: seated, back supported, feet flat, arm at heart level, appropriate cuff size) 1
- Cardiac exam: Displaced/sustained apical impulse (LVH), S4 gallop, irregular rhythm (atrial fibrillation) 1
- Vascular exam: Diminished peripheral pulses, carotid bruits, abdominal bruits (renovascular disease) 1
- Fundoscopic exam: Arteriovenous nicking, copper/silver wiring, hemorrhages, exudates, papilledema 1
- Body mass index elevation, increased waist circumference 1
Diagnostic Tests and Key Findings
Gold Standard for Diagnosis: Ambulatory blood pressure monitoring (ABPM) or home blood pressure monitoring (HBPM) to confirm office readings and exclude white coat hypertension 1.
Initial Diagnostic Workup
- Office blood pressure measurement: SBP ≥140 mm Hg or DBP ≥90 mm Hg on multiple occasions 1
- 12-lead ECG: Assess for LVH (Sokolow-Lyon index: SV1+RV5 ≥35 mm; Cornell index: SV3+RaVL >28 mm men, >20 mm women) 1
- Basic metabolic panel: Serum sodium, potassium, creatinine, eGFR 1
- Fasting lipid panel: Total cholesterol, LDL, HDL, triglycerides 1
- Fasting glucose or HbA1c: Screen for diabetes 1
- Urinalysis with albumin-to-creatinine ratio (UACR): Detect proteinuria/albuminuria 1
- Thyroid-stimulating hormone (TSH): Exclude thyroid disorders 1
- Serum uric acid: Often elevated in hypertension 1
Advanced Testing for HMOD
- Echocardiography: Most accurate assessment of LVH (LVMI: men >115 g/m², women >95 g/m²), left atrial volume, LV function 1
- Carotid ultrasound: Assess for atherosclerotic plaque, intima-media thickness 1
- Carotid-femoral pulse wave velocity: Measure arterial stiffness 1
- Brain MRI: If neurologic symptoms, cognitive decline (white matter lesions, microinfarcts) 1
Screening for Secondary Hypertension (when indicated)
Screen if: Age <30 years without risk factors, resistant hypertension, sudden BP deterioration, hypertensive emergency, or strong clinical clues 1.
- Renal ultrasound: Assess kidney size, rule out obstruction 1
- Plasma aldosterone/renin ratio: Screen for primary aldosteronism 1
- 24-hour urine metanephrines: Screen for pheochromocytoma 1
- Renal artery imaging (CT/MR angiography): If renovascular disease suspected 1
- Sleep study: If obstructive sleep apnea suspected 1
4. Management Summary
First-Line Treatments
All patients with confirmed hypertension should receive lifestyle modifications as foundational therapy 2. Pharmacologic treatment should be initiated based on BP level and cardiovascular risk 1.
Pharmacologic Treatment: First-Line Agents
For most patients, initiate with one of three first-line drug classes 2:
Specific Indications for Drug Selection:
- Diabetic nephropathy: ACE inhibitor or ARB (losartan reduces progression to end-stage renal disease) 7
- Heart failure with reduced ejection fraction: ACE inhibitor or ARB plus beta-blocker 6
- Post-myocardial infarction: ACE inhibitor (lisinopril reduces mortality) 6
- LVH with hypertension: ARB (losartan reduces stroke risk, but NOT in Black patients) 7
- Chronic kidney disease with eGFR <30 ml/min/1.73m²: Loop diuretic instead of thiazide 1
Treatment Duration: Lifelong therapy is typically required 2.
Second-Line Treatments
If BP remains uncontrolled on first-line therapy, add a second agent from a different class 2:
- Combination therapy: Thiazide + ACE inhibitor/ARB + calcium channel blocker 2
- Beta-blockers (atenolol 25-100 mg daily, metoprolol 50-200 mg daily) 5
- Alpha-blockers (doxazosin 1-16 mg daily) 5
Resistant Hypertension (BP >140/90 on 3+ drugs including diuretic)
First, exclude pseudoresistance (poor BP measurement, white coat effect, medication nonadherence, suboptimal drug choices) and secondary causes 1.
Fourth-line agent: Spironolactone 12.5-50 mg daily (if potassium <4.5 mmol/L and eGFR >45 ml/min/1.73m²) 1.
Alternatives if spironolactone contraindicated: Amiloride, eplerenone, doxazosin, clonidine, or beta-blockers 1.
Refer to specialist hypertension center for resistant hypertension management 1.
Non-Pharmacologic Treatment
Lifestyle modifications have additive BP-lowering effects and enhance medication efficacy 2:
- Weight loss: Target BMI <25 kg/m²; each 1 kg weight loss reduces BP by ~1 mm Hg 2
- DASH diet (Dietary Approaches to Stop Hypertension): Emphasize fruits, vegetables, whole grains, low-fat dairy, lean protein 1, 2
- Sodium restriction: Limit to <2 g/day (5 g salt/day); reduces BP by 5-6 mm Hg 2
- Potassium supplementation: Target 3.5-5 g/day through diet (bananas, potatoes, spinach) 2
- Physical activity: 150 minutes/week moderate-intensity aerobic exercise (brisk walking, cycling) 2
- Alcohol limitation: ≤2 drinks/day for men, ≤1 drink/day for women 2
- Smoking cessation: Mandatory for cardiovascular risk reduction 2
Treatment Targets
For most adults <65 years: Target BP <130/80 mm Hg 1.
For adults ≥65 years: Target SBP <130 mm Hg (if tolerated without excessive adverse effects) 2.
For patients with diabetes or chronic kidney disease: Target BP <130/80 mm Hg 1.
Reduce BP by 25% within first hour in hypertensive emergencies using IV agents (labetalol, nicardipine) 1, 3.
Key Monitoring Parameters
Symptoms to Monitor
- Dizziness, lightheadedness (excessive BP lowering) 2
- Fatigue, weakness (electrolyte abnormalities, medication side effects) 2
- Cough (ACE inhibitor side effect; switch to ARB) 2
- Peripheral edema (calcium channel blocker side effect) 2
Laboratory Monitoring
- Serum potassium and creatinine: Check 2-4 weeks after initiating ACE inhibitor/ARB/diuretic, then every 6-12 months 1
- Fasting lipids and glucose: Annually 1
- Urinary albumin-to-creatinine ratio: Annually if diabetes or chronic kidney disease 1
Blood Pressure Monitoring
- Office BP: Every 3-6 months once controlled, monthly during titration 1
- Home BP monitoring: Daily measurements (morning and evening) to assess control and adherence 1
- ABPM: Consider annually if white coat hypertension suspected or resistant hypertension 1
Follow-Up Intervals
- Routine follow-up: Every 3-6 months once BP controlled 1
- Increased monitoring: Monthly visits during medication titration or if BP uncontrolled 1
- Annual comprehensive assessment: ECG, labs, cardiovascular risk reassessment 1
Patient Education and Adherence
Key Education Points
- Hypertension is asymptomatic but causes serious complications (stroke, heart attack, kidney failure) if untreated 1
- Medication adherence is critical; most patients require lifelong therapy 2
- Lifestyle modifications are as important as medications and can reduce medication burden 2
- Home BP monitoring improves control and helps detect white coat hypertension 1
Warning Signs Requiring Immediate Attention
- Severe headache, confusion, vision changes 3
- Chest pain, shortness of breath 3
- Sudden weakness, numbness, speech difficulty (stroke symptoms) 3
- BP >180/120 mm Hg 3
Common Adherence Barriers
- Asymptomatic nature leads to poor medication adherence 1
- Medication side effects (cough, dizziness, fatigue, sexual dysfunction) 2
- Polypharmacy burden in patients with multiple comorbidities 2
- Cost of medications and lack of insurance coverage 1
- Health literacy and cultural beliefs about medication use 1
Strategies to improve adherence: Single-pill combination therapy, once-daily dosing, patient education, shared decision-making, addressing side effects promptly 1.
5. Functional and Contextual Factors
Impact on Quality of Life and Daily Functioning
- Uncontrolled hypertension is asymptomatic but leads to catastrophic events (stroke, myocardial infarction) that severely impair function 1
- Medication side effects (fatigue, dizziness, sexual dysfunction) can reduce quality of life and adherence 2
- Hypertensive emergencies cause acute disability from stroke, encephalopathy, or heart failure 3
- Chronic complications (heart failure, chronic kidney disease) progressively limit physical capacity and independence 1
Cultural Impacts
- African American patients have higher prevalence, earlier onset, and worse outcomes; may require more aggressive treatment and culturally tailored education 1
- Some cultures emphasize natural remedies over pharmaceuticals; requires respectful discussion of evidence-based benefits 1
- Socioeconomic barriers (lack of insurance, transportation, healthy food access) disproportionately affect minority and low-income populations 1
- Health literacy varies widely; use teach-back methods to ensure understanding 1
- Veterans with environmental exposures (burn pits, uranium) require targeted screening and management per VA/DoD guidelines 4
Prognostic Markers
Favorable Prognosis:
- BP controlled to target with treatment 2
- Absence of HMOD (no LVH, normal kidney function, no proteinuria) 1
- No additional cardiovascular risk factors 1
Poor Prognosis:
- Resistant hypertension increases risk of coronary disease, heart failure, stroke, end-stage renal disease, and all-cause mortality by 50% 1
- Presence of HMOD (LVH, reduced eGFR, albuminuria) significantly increases cardiovascular event risk 1
- Multiple cardiovascular risk factors (diabetes, smoking, dyslipidemia) synergistically increase risk 1
- Uncontrolled BP confers 3-fold increased cardiovascular risk compared to normotensive individuals 8
- Each 10 mm Hg SBP reduction decreases cardiovascular events by 20-30% 2
6. Quick Diagnostic Pattern Recognition
3-5 Cues That Strongly Suggest Hypertension
Persistently elevated office BP ≥140/90 mm Hg on multiple visits in an asymptomatic patient with obesity, family history, or age >50 years 1
Incidental finding of LVH on ECG (Sokolow-Lyon or Cornell criteria) or echocardiography in a patient with previously undiagnosed elevated BP 1
Proteinuria or elevated creatinine on routine screening in a patient with elevated BP readings, suggesting hypertensive nephropathy 1
Severe morning occipital headaches with BP >180/120 mm Hg, especially if accompanied by visual changes or confusion (hypertensive emergency) 3
Young patient (<30 years) with severe hypertension and hypokalemia, suggesting secondary cause (primary aldosteronism) requiring further workup 1