What are the steps for history taking, physical examination, differential diagnosis, investigation, management, and complication for various diseases, including conditions like hypertension?

Hypertension: Clinical Approach

History Taking

Obtain a focused history targeting cardiovascular risk, secondary causes, and medication adherence. 1

Essential Historical Elements

• Current blood pressure control status: Duration of hypertension, previous BP readings, current antihypertensive medications and doses, adherence patterns 1

• Cardiovascular risk factors: Personal history of diabetes, dyslipidemia, smoking, obesity, physical inactivity, family history of early-onset hypertension or stroke before age 40 1, 2

• Symptoms suggesting secondary hypertension: 1, 3

  • Sudden onset or worsening of hypertension, especially if young (<30 years) or older (>55 years) 1, 4
  • Resistant hypertension (uncontrolled on ≥3 medications including a diuretic) 1
  • Episodic symptoms: Paroxysmal headache, palpitations, pallor, perspiration (pheochromocytoma) 5, 4
  • Muscle cramps, weakness (primary aldosteronism with hypokalemia) 1, 5
  • Weight changes, heat/cold intolerance, tremor (thyroid disease) 4
  • Snoring, daytime somnolence, witnessed apneas (obstructive sleep apnea) 5

• Medication and substance history: 1

  • NSAIDs, cocaine, amphetamines, excessive alcohol, chronic steroids 1, 5, 4
  • Over-the-counter medications, herbal products, illicit drugs 1
  • Recent medication changes or discontinuation 6

• Symptoms of hypertensive emergency: 6

  • Severe headache, visual disturbances, chest pain, dyspnea 6
  • Focal neurological symptoms, altered mental status, seizures 6
  • Abdominal pain, nausea (less specific) 6

Physical Examination

Perform a targeted cardiovascular and neurological assessment with BP measurement in both arms. 2, 6

Critical Examination Components

• Blood pressure measurement: 2

  • Measure in both arms (>15 mmHg difference suggests aortic dissection or coarctation) 6, 4
  • Measure in lower extremity if coarctation suspected (BP higher in upper than lower extremities) 4
  • Repeat measurements on multiple occasions unless BP ≥180/110 mmHg 2

• Cardiovascular examination: 2

  • Cardiac auscultation for murmurs (aortic regurgitation causes widened pulse pressure with "water-hammer" pulse) 4
  • Abdominal bruit with diastolic component (renovascular hypertension) 4
  • Continuous murmur over back/chest (coarctation) 4
  • Absent or diminished femoral pulses (coarctation) 4

• Fundoscopic examination: 6

  • Papilledema, hemorrhages, exudates (hypertensive emergency) 6

• Neurological examination: 6

  • Mental status, focal deficits, signs of encephalopathy 6
  • Somnolence, lethargy, cortical blindness (hypertensive encephalopathy) 6

• Physical signs of secondary causes: 1, 4

  • Truncal obesity, purple striae, facial rounding (Cushing syndrome) 4
  • Bilateral upper abdominal masses (polycystic kidney disease) 3

Differential Diagnosis from History and Physical Examination

Primary vs. Secondary Hypertension

Primary (essential) hypertension is diagnosed after excluding secondary causes, which account for approximately 10% of cases. 1

Secondary Causes to Exclude Based on Clinical Presentation

• Renovascular hypertension: Onset before age 30 or after age 55, abdominal bruit with diastolic component, acute renal failure with ACE inhibitor/ARB initiation 4

• Primary aldosteronism: Resistant hypertension, spontaneous or diuretic-induced hypokalemia, family history of early-onset hypertension 1, 5

• Pheochromocytoma: Labile hypertension with paroxysmal headache, palpitations, pallor, perspiration 5, 4

• Obstructive sleep apnea: Snoring, daytime somnolence, witnessed apneas causing BP lability 5

• Cushing syndrome: Truncal obesity, glucose intolerance, purple striae, facial rounding 4

• Hyperthyroidism: Weight loss, palpitations, heat intolerance, tremor, widened pulse pressure 4

• Hyperparathyroidism: Hypercalcemia on metabolic panel 4

• Chronic kidney disease: Elevated creatinine, abnormal urinalysis, decreased estimated GFR 4

• Aortic coarctation: BP higher in upper than lower extremities, absent femoral pulses, continuous murmur 4

• Aortic regurgitation: Widened pulse pressure with "water-hammer" pulse, diastolic murmur 4

• Drug-induced: NSAIDs, cocaine, amphetamines, excessive alcohol, chronic steroids 1, 5, 4

White Coat vs. Masked Hypertension

• White coat hypertension: Elevated office BP (≥140/90 mmHg) with normal out-of-office BP 7, 5
• Masked hypertension: Normal office BP with elevated out-of-office BP 7, 5

Hypertensive Emergency vs. Urgency

• Hypertensive emergency: BP ≥180/110 mmHg with acute end-organ damage (encephalopathy, stroke, acute coronary syndrome, pulmonary edema, acute renal failure, aortic dissection) 6, 8
• Hypertensive urgency: Severe BP elevation (≥180/110 mmHg) without acute end-organ damage 8

Investigations

Obtain basic laboratory testing for all patients, with additional testing based on clinical suspicion for secondary causes. 9, 1

Initial Laboratory Testing (All Patients)

• Basic metabolic panel: Serum sodium, potassium, creatinine, estimated GFR, calcium 9, 1, 4
• Fasting blood glucose and lipid profile 9, 1, 4
• Complete blood count 9, 4
• Thyroid-stimulating hormone 9, 4
• Urinalysis: Protein, erythrocytes, leucocytes, casts 9, 6
• Electrocardiogram: Left ventricular hypertrophy, ischemia, arrhythmias 9, 6

Out-of-Office Blood Pressure Monitoring

Home blood pressure monitoring (HBPM) is the most practical option for confirming hypertension diagnosis and detecting white coat or masked hypertension. 7

• HBPM protocol: Two readings morning and evening for minimum 3 days 7
• Ambulatory blood pressure monitoring (ABPM): More sensitive for detecting masked hypertension (25.8% prevalence) than HBPM (11.1% prevalence) 7
• Diagnostic thresholds: Office BP 120-139/70-89 mmHg or 140-159/90-99 mmHg should be confirmed with ABPM or HBPM 2
• Immediate confirmation needed: BP 160-179/100-109 mmHg within 1 month, preferably by HBPM or ABPM 2

Additional Testing for Suspected Secondary Hypertension

Screen for secondary causes when patient is young, hypertension is resistant to treatment, or specific clinical features are present. 1

• Primary aldosteronism screening: 1

  • Plasma aldosterone-to-renin activity ratio (recommended screening test) 1
  • Indicated for: Resistant hypertension, spontaneous or substantial diuretic-induced hypokalemia, adrenal incidentaloma, family history of early-onset hypertension or stroke <40 years 1
  • Referral to hypertension specialist or endocrinologist if positive 1

• Pheochromocytoma: 24-hour urinary metanephrines 4

• Cushing syndrome: Dexamethasone suppression test 4

• Renovascular disease: 4

  • Renal artery Doppler ultrasound, CT angiography, or MRA 4
  • Indicated for: Onset before age 30 or after age 55, abdominal bruit, accelerated hypertension, acute renal failure with ACE inhibitor/ARB 4

• Renal parenchymal disease: Renal ultrasound for kidney size, cortical thickness, masses, obstruction 3

• Coarctation: CT angiography or MRA of thorax and abdomen 4

Testing for Hypertensive Emergency

• Troponin-T, CK, CK-MB: If acute coronary syndrome suspected 6
• Peripheral blood smear: Schistocytes for thrombotic microangiopathy 6
• Chest X-ray: Pulmonary edema 6
• Echocardiography or point-of-care ultrasound: Cardiac function, pulmonary edema 6
• CT or MRI brain: Intracranial hemorrhage, hypertensive encephalopathy 6
  • MRI with FLAIR imaging shows posterior reversible leukoencephalopathy syndrome (PRES) 6
• CT angiography: Aortic dissection 6
• Lactic dehydrogenase (LDH), haptoglobin: Thrombotic microangiopathy 6

Optional Testing

• Echocardiogram: Left ventricular hypertrophy, cardiac function 9
• 24-hour ambulatory BP monitoring: Quantify BP patterns and cardiovascular risk 5, 4
• Pulse wave velocity: Quantify arterial stiffness 4
• Urinary albumin-to-creatinine ratio: Detect early kidney damage 9

Management

First-line therapy is lifestyle modification for all patients, with pharmacological treatment based on BP level and cardiovascular risk. 1, 10

Lifestyle Modifications (All Patients)

• Weight loss: If overweight or obese 10
• Dietary changes: 10
  • DASH (Dietary Approaches to Stop Hypertension) eating plan 10
  • Sodium reduction (<2.3 g/day, ideally <1.5 g/day) 10
  • Potassium supplementation (unless contraindicated) 10
• Physical activity: Regular aerobic exercise (150 minutes/week moderate intensity) 10
• Alcohol moderation or elimination: Limit to ≤2 drinks/day for men, ≤1 drink/day for women 10
• Smoking cessation: If applicable 11

Pharmacological Treatment Thresholds

Initiate antihypertensive medication based on BP level and atherosclerotic CVD risk. 1

• BP ≥140/90 mmHg: Initiate medication regardless of CVD risk 1
• BP 130-139/80-89 mmHg (Stage 1): Initiate medication if:
  • Clinical CVD present 9
  • 10-year ASCVD risk ≥10% (using ACC/AHA Pooled Cohort Equations for ages 40-79) 9
  • Diabetes or chronic kidney disease present 1

First-Line Pharmacological Therapy

First-line drug therapy consists of thiazide/thiazide-like diuretics, ACE inhibitors or ARBs, and calcium channel blockers. 10

• Thiazide or thiazide-like diuretic: Hydrochlorothiazide or chlorthalidone (chlorthalidone preferred based on clinical trial data) 10, 12
• ACE inhibitor or ARB: Enalapril, lisinopril, candesartan 10
  • Contraindications: Pregnancy (causes fetal/neonatal morbidity and mortality), bilateral renal artery stenosis, history of angioedema 13
  • Monitoring: Serum creatinine and potassium within 2 weeks of initiation 13
  • Adverse effects: Cough (5-10%), hyperkalemia, acute renal failure, angioedema (0.1%, higher in Black patients) 13
• Calcium channel blocker: Amlodipine 10

Treatment Targets

Target BP <130/80 mmHg for adults <65 years; SBP <130 mmHg for adults ≥65 years. 10

• Titrate medications according to office and home BP readings 10
• SBP reduction of 10 mmHg decreases CVD events by 20-30% 10

Resistant Hypertension Management

Resistant hypertension is defined as BP uncontrolled on ≥3 medications including a diuretic at optimal doses. 14

• Exclude pseudoresistance: Poor adherence, white coat hypertension, improper BP measurement technique 14
• Exclude secondary causes: Screen as outlined above 14
• Eliminate interfering substances: NSAIDs, excessive alcohol, sympathomimetics 14
• Optimize regimen: 14
  • Ensure medications at optimal doses with complementary mechanisms 14
  • Add appropriate diuretic if not already prescribed 14
• Add mineralocorticoid receptor antagonist: Spironolactone or eplerenone as fourth agent (effective even without biochemical aldosterone excess) 14

Management of Secondary Hypertension

Renovascular Hypertension

Medical therapy with renin-angiotensin system blockade is first-line for most atherosclerotic renovascular hypertension. 7

• Unilateral lesions: Manage medically with ACE inhibitor or ARB, periodic surveillance of contralateral kidney 7
• Consider angioplasty for: 7
  • Fibromuscular dysplasia (angioplasty without stents) 7
  • Younger patients with sudden onset hypertension 7
  • Bilateral hemodynamically significant stenosis (>75%) 7
  • Flash pulmonary edema or creatinine rise >30% with renin-angiotensin system blockade 7
• Stents needed: For atherosclerotic lesions to maintain long-term patency 7

Primary Aldosteronism

Refer to hypertension specialist or endocrinologist for further evaluation and treatment after positive screening. 1

Hypertensive Emergency Management

Admit to intensive care unit for immediate BP reduction with short-acting titratable intravenous antihypertensive. 8

• Target: Reduce mean arterial pressure by 10-20% in first hour, then to 160/100 mmHg over next 2-6 hours 8
• Preferred IV agents: 8
  • Labetalol, esmolol, fenoldopam, nicardipine, clevidipine 8
• Use with caution: Sodium nitroprusside (toxicity risk) 8
• Avoid: Hydralazine, immediate-release nifedipine, nitroglycerin 8
• Exclude hypertensive emergency: When BP ≥180/110 mmHg 2

Hypertensive Urgency Management

Treat with oral antihypertensives as outpatient with close follow-up. 8

• Reduce BP over days, not hours 8
• Avoid rapid-acting IV agents 8

Complications

Uncontrolled hypertension leads to cardiovascular, renal, and neurological complications. 1, 10

Cardiovascular Complications

• Coronary heart disease: Myocardial infarction, angina 10
• Heart failure: Both reduced and preserved ejection fraction 10
• Left ventricular hypertrophy: Precursor to heart failure 9
• Aortic dissection: Hypertensive emergency 6
• Atrial fibrillation: Increased risk with hypertension 13

Cerebrovascular Complications

• Stroke: Ischemic and hemorrhagic 10
• Transient ischemic attacks 13
• Hypertensive encephalopathy: Posterior reversible leukoencephalopathy syndrome (PRES) 6
• Cognitive impairment: Widened pulse pressure independently predicts increased risk 4

Renal Complications

• Chronic kidney disease progression: Accelerated decline in GFR 4
• Acute renal failure: Hypertensive emergency 6
• End-stage renal disease: Requiring dialysis 11
• Proteinuria and microalbuminuria: Early markers of kidney damage 9

Ophthalmologic Complications

• Hypertensive retinopathy: Hemorrhages, exudates, papilledema 6
• Visual loss: From retinal damage or stroke 13

Complications of Hypertensive Emergency

• Thrombotic microangiopathy: Hemolytic anemia, thrombocytopenia, acute kidney injury 6
• Pulmonary edema: Acute heart failure 6
• Intracranial hemorrhage: Stroke 6
• Acute coronary syndrome: Myocardial infarction 6

Medication-Related Complications

• ACE inhibitors/ARBs: 13
  • Angioedema (0.1%, potentially fatal) 13
  • Hyperkalemia 13
  • Acute renal failure (especially with bilateral renal artery stenosis) 13
  • Fetal/neonatal morbidity and mortality if used in pregnancy 13
  • Cough (common, not dangerous) 13
  • Hypotension (especially first dose) 13
• Diuretics: Hypokalemia, hyponatremia, hyperglycemia 3