Types of Hypertension

A. Primary (Essential) Hypertension

• Prevalence: Accounts for ~90% of adult cases.
• Characteristics:
  • Develops gradually over years.
  • No identifiable cause.
• Contributing Factors:
  • Ageing, lifestyle (e.g., high sodium intake, sedentary habits), genetics, and atherosclerosis.

B. Secondary Hypertension

• Characteristics:
  • Arises from an underlying condition or medication.
  • Appears suddenly and often more severe than primary hypertension.
• Causes:
  • Medical Conditions:
    • Kidney disease, adrenal tumours, congenital heart defects, obstructive sleep apnoea, thyroid dysfunction.
  • Medications:
    • NSAIDs, oral contraceptives, immunosuppressants.
  • Substance Use:
    • Cocaine, amphetamines.

C. Other Types

• White Coat Hypertension: Elevated BP in healthcare settings; normal at home.
• Masked Hypertension: Normal BP in healthcare settings; elevated at home.
• Sustained Hypertension: Consistently elevated BP in all settings.
• Nocturnal Hypertension: BP elevation during sleep.

Pathophysiology of Hypertension

Hypertension results from complex interactions between genetic, environmental, and physiological factors that affect cardiac output and vascular resistance.

A. Determinants of Blood Pressure

1. Cardiac Output (CO):
   • Volume of blood pumped by the heart.
   • Increased by higher heart rate or stroke volume.
2. Total Peripheral Resistance (TPR):
   • Resistance in the arterial system.
   • Increased by vasoconstriction or arterial narrowing.

B. Key Mechanisms

1. Atherosclerosis:
   • Plaque build-up narrows arteries → increased resistance and BP.
2. Endothelial Dysfunction:
   • Impaired production of vasodilators like nitric oxide → Vasoconstriction.
3. Neurohormonal Dysregulation:
   • Overactivation of the sympathetic nervous system (SNS) and renin-angiotensin-aldosterone system (RAAS).

Complications of Hypertension

Untreated hypertension can damage blood vessels and organs, leading to severe health issues.

A. Cardiovascular Complications

1. Heart Attack:
   • Atherosclerosis increases coronary artery blockage risk.
2. Stroke:
   • Hypertension damages brain arteries, causing blockages or ruptures.
3. Heart Failure:
   • Increased workload thickens heart muscle → Impaired pumping ability.
4. Aneurysms:
   • Weak vessel walls bulge, risking rupture.
5. Arrhythmias:
   • Can result in sudden cardiac death.

B. Organ Damage

1. Kidney Disease:
   • Damaged renal vessels impair filtration → Potential kidney failure.
2. Eye Damage:
   • Retinopathy from vessel damage can lead to vision loss.
3. Cognitive Impairment:
   • Reduced brain perfusion contributes to dementia.
4. Metabolic Syndrome:
   • Clustering of high BP, dyslipidemia, obesity, and insulin resistance increases cardiovascular risk.

Importance of Blood Pressure Management

A. Regular Monitoring

• Early detection is key to preventing complications.
• Home monitoring and regular healthcare visits improve diagnosis and control

B. Lifestyle Modifications

1. Diet:
   • Sodium Reduction: Aim for <1500 mg/day.
   • DASH Diet: Emphasise fruits, vegetables, whole grains, and lean proteins.
   • Potassium Intake: 3500–5000 mg/day from foods like bananas, avocados, and spinach.
2. Exercise:
   • 150 minutes of moderate-intensity activity weekly.
   • Strength training at least twice-weekly.
3. Weight Management:
   • Even modest weight loss significantly reduces BP.
4. Other Changes:
   • Quit smoking, limit alcohol, and manage stress.

C. Pharmacological Treatment

• Indications: Required for many patients to achieve target BP (<130/80 mmHg).
• Medication Classes:
  1. Diuretics: Reduce blood volume.
  2. ACE Inhibitors/ARBs: Inhibit RAAS effects.
  3. Beta-Blockers: Reduce heart rate and cardiac output.
  4. Calcium Channel Blockers: Relax vascular smooth muscle.
• Role of Pharmacists:
  • Educate patients on proper use and adherence.
  • Monitor for side effects.
  • Adjust regimens in collaboration with physicians.

Key Takeaways

1. Hypertension Types: Distinguish primary from secondary and other subtypes.
2. Mechanisms: Understand the contributions of vascular resistance, cardiac output, and neurohormonal dysregulation.
3. Complications: Highlight the systemic impact of prolonged, uncontrolled hypertension.
4. Management: Emphasise the importance of lifestyle changes and medication adherence for optimal outcomes.

References

1. World Health Organization. (n.d.). Hypertension Fact Sheet. Retrieved from WHO
2. Mayo Clinic. (n.d.). High Blood Pressure (Hypertension): Symptoms and Causes. Retrieved from Mayo Clinic
3. Cleveland Clinic. (n.d.). Hypertension (High Blood Pressure). Retrieved from Cleveland Clinic
4. American Heart Association. (n.d.). The Facts About High Blood Pressure. Retrieved from AHA