L5 - Hypertension

Overview of Hypertension

• Hypertension, commonly known as high blood pressure, is a major health issue worldwide.

• Described as the "silent killer" because it usually presents no symptoms until serious complications arise.

• Typically diagnosed when blood pressure readings reach 140/90 mmHg or higher.

• Affects approximately 1 billion people globally, with rising incidence due to aging populations, urbanization, and lifestyle changes.

Risks and Complications

• Major risk factors include genetics, lifestyle choices, and underlying health conditions.

• Uncontrolled hypertension can lead to serious health issues such as:

  • Cardiovascular Disease: Heart failure, myocardial infarction (heart attack), and atrial fibrillation.

  • Stroke: Ischaemic and haemorrhagic strokes due to damaged arteries.

  • Kidney Disease: Chronic kidney disease and possibly requiring dialysis or transplantation.

  • Retinopathy: Leading to visual impairment or blindness due to damage to retina blood vessels.

  • Cognitive Decline: Increased risk of dementia and Alzheimer’s disease due to poor cerebral blood flow.

Pathophysiology Insights

• Hypertension arises from a combination of genetic, neurohormonal, and vascular factors.

• An overactive sympathetic nervous system leads to increased heart rate and vasoconstriction.

• The Renin-Angiotensin-Aldosterone System (RAAS) regulates blood pressure through sodium and water retention as well as vascular tone.

• Endothelial dysfunction plays a crucial role by reducing nitric oxide production (vasodilation) and increasing vasoconstrictors.

• Salt Sensitivity: Variability among individuals in how blood pressure responds to salt intake.

Classification of Hypertension

• Primary (Essential) Hypertension: Accounts for about 95% of cases, often idiopathic.

• Secondary Hypertension: Caused by underlying conditions such as:

  • Renal causes (chronic kidney disease, renovascular hypertension).

  • Endocrine causes (Cushing's syndrome, Conn's syndrome).

  • Neurological causes (obstructive sleep apnea).

  • Drug-induced hypertension (oral contraceptives, NSAIDs).

Diagnosis and Monitoring

• Diagnosis requires consistent blood pressure readings over time, not a single measurement.

• Blood pressure should be taken manually or digitally in a relaxed state after sitting for five minutes.

• Ambulatory Blood Pressure Monitoring (ABPM): Continuous monitoring to detect conditions like white coat hypertension.

• Home monitoring is encouraged for ongoing assessment and management.

Clinical Presentation and Signs

• Many individuals are asymptomatic until significant complications occur.

• Severe hypertension may present with:

  • Morning headaches and dizziness.

  • Blurred vision or nosebleeds.

  • Shortness of breath and chest pain (angina).

  • Fatigue or confusion related to cerebral perfusion.

• Hypertensive Crisis: Blood pressure greater than 180/120 mmHg requiring urgent medical attention.

End Organ Damage Assessment

• Chronic hypertension can lead to irreversible damage:

  • Cardiac: Heart failure, myocardial damage, arrhythmias.

  • Cerebral: Stroke, vascular dementia.

  • Renal: Chronic kidney disease and failure.

  • Ocular: Hypertensive retinopathy.

Risk Factor Determination

• Key determinants include:

  • Blood pressure levels, age, smoking status, diabetes, dyslipidemia, and obesity.

• A comprehensive cardiovascular risk assessment is essential for guiding treatment decisions.

Treatment and Management Strategies

• Early detection and effective management through:

  • Lifestyle changes such as diet and exercise.

  • Medications to manage blood pressure levels.

  • Regular monitoring of blood pressure to prevent complications.

• Reductions in blood pressure can significantly lower the risk of strokes and heart diseases.

Key Takeaways

• Hypertension is prevalent and poses significant health risks.

• Requires systematic monitoring and personalized treatment approaches.

• Collaborative management with dietitians and other health professionals plays a crucial role in addressing lifestyle factors.