Summary of "Hypertension | Clinical Medicine"

Summary of Main Ideas and Concepts on Hypertension

Types of Hypertension:
- Essential (Primary) Hypertension: Accounts for about 90% of cases; causes are not well-defined.
- Secondary Hypertension: Accounts for about 10% of cases; often due to identifiable conditions.
Causes of Essential Hypertension:
- Vascular Changes: Thickening of blood vessel walls reduces diameter, increasing systemic vascular resistance and blood pressure.
- Age: Older individuals are more prone due to calcification and thickening of vessels.
- Lifestyle Factors: Smoking, obesity, high sodium diet, and stress contribute to hypertension.
Causes of Secondary Hypertension:
- Renal Causes: Chronic kidney disease and renal artery stenosis can increase blood pressure through the renin-angiotensin-aldosterone system.
- Endocrine Disorders: Conditions like hyperthyroidism, hypothyroidism, hyperaldosteronism, Cushing's syndrome, and pheochromocytoma can lead to hypertension.
- Neurological Disorders: Increased intracranial pressure can lead to Cushing's triad (hypertension, bradycardia, irregular respirations).
- Aortic Diseases: Coarctation of the aorta leads to differential blood pressure readings between upper and lower extremities.
- Preeclampsia/Eclampsia: High blood pressure in pregnant women characterized by proteinuria and edema.
- Substance Use: Stimulants like cocaine and amphetamines can elevate blood pressure.
- Sleep Apnea: Associated with periods of apnea leading to sympathetic activation and increased blood pressure.
Blood Pressure Classification:
- Normal: <120/80 mmHg
- Pre-hypertensive: 120-129/<80 mmHg
- Stage 1 Hypertension: 130-139/80-89 mmHg
- Stage 2 Hypertension: ≥140/≥90 mmHg
- Hypertensive Urgency: >180/120 mmHg without target organ damage
- Hypertensive Emergency: >180/120 mmHg with target organ damage
Complications of Hypertension:
- Cardiovascular: Left ventricular hypertrophy, heart failure, atherosclerosis leading to coronary artery disease, myocardial infarction, and aortic dissection/aneurysm.
- Neurological: Transient ischemic attacks (TIAs), strokes, and hemorrhagic events.
- Renal: Chronic kidney disease and acute kidney injury.
- Retinal Disease: Hypertensive retinopathy characterized by changes in retinal blood vessels.
Diagnostic Approach:
- Measure blood pressure in both arms to rule out conditions like aortic dissection.
- Confirm hypertension with multiple readings across different visits.
- Assess for white coat hypertension using home monitoring.
Treatment Guidelines:
- Lifestyle Modifications: Recommended for all patients, including weight loss, dietary changes (DASH diet), and exercise.
- Medications:
  - Stage 1: Start antihypertensives if cardiovascular risk is >10%.
  - Stage 2: Initiate antihypertensive therapy regardless of cardiovascular risk.
  - Common medications include ACE inhibitors, ARBs, thiazide diuretics, and calcium channel blockers.
  - Specific medications based on comorbid conditions (e.g., beta-blockers for coronary artery disease).
- Management of Hypertensive Crises:
  - For urgency, aim to lower blood pressure gradually.
  - For emergencies, use IV medications and monitor closely to avoid rapid drops in blood pressure.