Hypertension — Diagnosis, Management, and Secondary Causes

Hypertension is defined as persistently elevated blood pressure (BP) ≥130/80 mmHg based on the 2017 ACC/AHA Guidelines. It affects approximately 45% of U.S. adults and is a major modifiable risk factor for cardiovascular disease, stroke, and chronic kidney disease.

[KEY_CONCEPT] Blood Pressure Classification (ACC/AHA 2017):

Epidemiology & Risk Factors:

• Primary (essential) hypertension accounts for 90-95% of cases
• Secondary hypertension comprises 5-10% of cases
• Risk factors include age, family history, obesity, diabetes, high sodium intake, physical inactivity, and excessive alcohol consumption

[HIGH_YIELD] Pathophysiology involves increased peripheral vascular resistance through:

• Increased sympathetic nervous system activity
• Renin-angiotensin-aldosterone system (RAAS) activation
• Endothelial dysfunction
• Sodium retention and volume expansion

[CLINICAL_PEARL] Hypertension is often called the "silent killer" because most patients are asymptomatic until complications develop, emphasizing the importance of routine screening.

Most patients with hypertension are asymptomatic, making routine blood pressure screening essential. When symptoms occur, they are often related to end-organ damage or hypertensive emergencies.

Asymptomatic Hypertension:

• Discovered incidentally during routine visits
• May have subtle symptoms: fatigue, mild headaches

Symptomatic Presentations:

[HIGH_YIELD] Signs suggesting secondary hypertension:

• Onset <30 years or >55 years
• Resistant hypertension (uncontrolled on 3+ medications)
• Severe hypertension (>180/110 mmHg)
• Accelerated hypertension (rapid BP rise with end-organ damage)

Physical Examination Findings:

End-Organ Damage Manifestations:

• Cardiovascular: Left ventricular hypertrophy, heart failure, coronary artery disease
• Cerebrovascular: Stroke, transient ischemic attacks, cognitive impairment
• Renal: Chronic kidney disease, proteinuria, hematuria
• Retinal: Hypertensive retinopathy, papilledema

[CLINICAL_PEARL] Hypertensive Emergency presents with severe hypertension (>180/120 mmHg) PLUS acute end-organ damage requiring immediate treatment. Hypertensive Urgency is severe hypertension WITHOUT acute end-organ damage.

Red Flag Symptoms requiring urgent evaluation:

• Chest pain or shortness of breath
• Neurological symptoms (headache, vision changes, altered mental status)
• Acute kidney injury
• Severe headache with nausea/vomiting

[KEY_CONCEPT] Accurate Blood Pressure Measurement Technique:

Proper BP Measurement Protocol:

1. Patient seated quietly for 5 minutes
2. Feet flat on floor, arm supported at heart level
3. Appropriate cuff size (bladder width 40% of arm circumference)
4. Two readings 1-2 minutes apart
5. Average the two readings
6. Confirm elevated readings on ≥2 separate occasions

Diagnostic Criteria:

• Hypertension diagnosis requires:
  • Average BP ≥130/80 mmHg on ≥2 separate occasions, OR
  • Single reading ≥140/90 mmHg with evidence of end-organ damage

[HIGH_YIELD] Out-of-Office BP Monitoring:

• Ambulatory BP Monitoring (ABPM): Gold standard for confirming diagnosis
• Home BP Monitoring: Alternative when ABPM unavailable
• White coat hypertension: Elevated office BP, normal out-of-office BP
• Masked hypertension: Normal office BP, elevated out-of-office BP

Initial Evaluation Workup:

[CLINICAL_PEARL] Secondary Hypertension Screening Indications:

Screen for Secondary Causes When:

• Age <30 or >55 years at onset
• Resistant hypertension (uncontrolled on ≥3 medications including diuretic)
• Severe hypertension (≥180/110 mmHg)
• Acute rise in previously controlled BP
• Clinical features suggesting specific causes

Secondary Hypertension Workup:

Secondary HTN Diagnostic Algorithm:

Renal Disease: • Creatinine, BUN, urinalysis • Renal ultrasound • If indicated: Renal arteriography

Endocrine: • Primary aldosteronism: Aldosterone/renin ratio • Pheochromocytoma: 24-hour urine metanephrines • Cushing syndrome: 24-hour urine cortisol • Thyroid function tests

Vascular: • Coarctation: Echocardiogram, CT/MRI • Renal artery stenosis: Renal artery duplex

[KEY_CONCEPT] 2017 ACC/AHA Treatment Thresholds:

Lifestyle Modifications (First-line for all patients):

[HIGH_YIELD] DASH Diet and Lifestyle:

• Weight loss: 1 kg reduction → 1 mmHg SBP reduction
• DASH diet: Emphasizes fruits, vegetables, whole grains, lean proteins
• Sodium restriction: <2.3g/day (ideal <1.5g/day)
• Physical activity: 150 minutes moderate aerobic exercise/week
• Alcohol limitation: Men ≤2 drinks/day, women ≤1 drink/day
• Smoking cessation

Pharmacologic Management:

Antihypertensive Treatment Algorithm:

1st Line Agents (RAAS inhibitors + Diuretics + CCBs): ├─ ACE inhibitors (lisinopril, enalapril) ├─ ARBs (losartan, valsartan) ├─ Thiazide diuretics (HCTZ, chlorthalidone) └─ Calcium channel blockers (amlodipine, nifedipine)

2nd Line: ├─ Beta-blockers (metoprolol, atenolol) ├─ Aldosterone antagonists (spironolactone) └─ Alpha-blockers (doxazosin)

Combination Therapy: • Start with 2 agents if BP >20/10 mmHg above target • Preferred combinations:

• ACE inhibitor + thiazide diuretic
• ARB + calcium channel blocker
• ACE inhibitor + calcium channel blocker

[HIGH_YIELD] Target Blood Pressure Goals:

• General population: <130/80 mmHg
• Diabetes: <130/80 mmHg
• CKD: <130/80 mmHg
• Age ≥65 years: <130/80 mmHg (if tolerated)

Special Populations:

[CLINICAL_PEARL] Resistant Hypertension Management:

1. Confirm true resistance (proper BP technique, medication adherence)
2. Screen for secondary causes
3. Optimize lifestyle modifications
4. Add spironolactone (most effective 4th agent)
5. Consider referral to hypertension specialist

Acute Complications:

[HIGH_YIELD] Hypertensive Emergency (Malignant Hypertension):

• BP >180/120 mmHg WITH acute end-organ damage
• Target: Reduce BP by 10-20% in first hour, then gradual reduction
• Avoid: Precipitous BP reduction (risk of stroke, MI, acute kidney injury)
• Treatment: IV nicardipine, clevidipine, or labetalol

Hypertensive Urgency:

• Severe hypertension WITHOUT acute end-organ damage
• Treatment: Oral antihypertensives, gradual reduction over 24-48 hours

Chronic Complications:

[KEY_CONCEPT] End-Organ Damage:

Monitoring & Follow-up:

Hypertension Monitoring Schedule:

Initial Monitoring: ├─ Weekly visits until BP controlled ├─ Medication titration every 2-4 weeks └─ Home BP monitoring recommended

Stable/Controlled: ├─ Office visits every 3-6 months ├─ Annual laboratory monitoring: │ ├─ Basic metabolic panel │ ├─ Lipid profile │ ├─ HbA1c (if diabetic) │ └─ Urinalysis └─ Annual screening: ├─ Fundoscopic exam ├─ ECG └─ Cardiovascular risk assessment

[CLINICAL_PEARL] Medication Adherence:

• Non-adherence is the most common cause of apparent resistant hypertension
• Use combination pills when possible to improve adherence
• Address cost barriers and side effects

Quality Measures:

• BP control rate <140/90 mmHg (older guideline target)
• BP control rate <130/80 mmHg (current ACC/AHA target)
• Medication adherence rates
• Lifestyle counseling documentation

[HIGH_YIELD] Pregnancy Considerations:

• Chronic hypertension: Present before 20 weeks gestation
• Gestational hypertension: Develops after 20 weeks
• Preeclampsia: Hypertension + proteinuria + end-organ damage
• Treatment: Labetalol, nifedipine, methyldopa (safe in pregnancy)

Prognosis:

[HIGH_YIELD] Cardiovascular Risk Reduction:

• Every 10 mmHg SBP reduction decreases:
  • Stroke risk by 27%
  • Heart failure risk by 28%
  • Coronary heart disease risk by 17%
  • All-cause mortality by 13%

Risk Stratification:

[KEY_CONCEPT] Primary Prevention Strategies:

Population-Level Interventions:

• Sodium reduction in food supply
• Trans fat elimination
• Tobacco control policies
• Physical activity promotion

Individual-Level Prevention:

• Regular BP screening (annually for normal BP, more frequently if elevated)
• Lifestyle counseling for all adults
• Early identification and treatment of modifiable risk factors

Secondary Prevention:

Secondary Prevention Strategy:

1. Optimal BP Control: ├─ Target <130/80 mmHg ├─ Medication adherence └─ Home BP monitoring

2. Comprehensive Risk Factor Management: ├─ Statin therapy (if indicated) ├─ Diabetes management (HbA1c <7%) ├─ Smoking cessation └─ Aspirin (if bleeding risk acceptable)

3. Lifestyle Optimization: ├─ DASH diet ├─ Weight management ├─ Regular exercise └─ Stress management

[CLINICAL_PEARL] Long-term Outcomes:

• Well-controlled hypertension has excellent prognosis
• Time to benefit: CV risk reduction begins within months of treatment initiation
• Legacy effect: Early aggressive treatment provides long-term benefits even if later control becomes suboptimal

Follow-up Considerations:

• Medication adherence remains the biggest challenge
• Lifestyle maintenance requires ongoing support and counseling
• Comorbidity management (diabetes, dyslipidemia) is essential
• Patient education about the asymptomatic nature of hypertension

[HIGH_YIELD] Special Considerations:

• Elderly patients: Balance BP reduction with fall risk
• Diabetes: Intensive BP control may reduce microvascular complications
• CKD: BP control slows progression to ESRD
• Post-stroke: Gradual BP reduction after acute phase

Cost-Effectiveness:

• Hypertension treatment is among the most cost-effective medical interventions
• Generic medications provide excellent outcomes at low cost
• Prevention of one stroke or MI justifies years of antihypertensive therapy