Treatment of Hypertension

• What system primarily regulates short-term blood pressure control?

  The baroreceptor reflex, mediated by the autonomic nervous system (ANS).
• Where are the main baroreceptors located, and what do they detect?

  The carotid sinus and aortic arch; they detect changes in arterial blood pressure via stretch receptors.
• How do baroreceptors respond to an increase in blood pressure?

  They increase their firing rate → activate the parasympathetic nervous system → inhibit sympathetic output → decrease heart rate (bradycardia) and vasodilation → lowers BP.
• How do baroreceptors respond to a decrease in blood pressure?

  They decrease firing rate → reduce parasympathetic activity and increase sympathetic activity → increases heart rate (tachycardia), cardiac contractility, and vasoconstriction → raises BP.
• What role does the medulla oblongata play in BP regulation?

  It processes signals from baroreceptors and modulates sympathetic and parasympathetic output via the nucleus tractus solitarius (NTS).
• What is the function of the chemoreceptor reflex in blood pressure regulation?

  It detects hypoxia, hypercapnia, and acidosis → increases sympathetic activity → vasoconstriction → raises BP to maintain perfusion.
• How do catecholamines affect short-term BP regulation?

  Adrenal medulla releases epinephrine and norepinephrine → bind to α1 receptors (vasoconstriction) and β1 receptors (increased heart rate and contractility) → increase BP.
• What system is primarily responsible for long-term BP regulation?

  The renin-angiotensin-aldosterone system (RAAS).
• What triggers renin release from the kidneys?

  • Low renal perfusion pressure (detected by juxtaglomerular cells)
  • Sympathetic stimulation (via β1 adrenergic receptors)
  • Low sodium concentration at the macula densa
• What is the function of renin in BP regulation?

  Converts angiotensinogen (produced by the liver) into angiotensin I.
• How does angiotensin I become angiotensin II?

  Angiotensin-converting enzyme (ACE) in the lungs converts angiotensin I into angiotensin II.
• What are the effects of angiotensin II on blood pressure?

  • Potent vasoconstriction (increases systemic vascular resistance → raises BP)
  • Stimulates aldosterone release from the adrenal cortex → increases sodium and water retention → increases blood volume → raises BP
  • Stimulates ADH (vasopressin) release → water retention in kidneys → increases blood volume
• How does aldosterone contribute to long-term BP regulation?

  Increases sodium and water reabsorption in the distal tubules of the kidney → expands blood volume → raises BP.
• How does antidiuretic hormone (ADH) affect BP?

  Increases water reabsorption in the collecting ducts of the kidneys → increases blood volume → raises BP.
• How does atrial natriuretic peptide (ANP) counteract hypertension?

  Released from atria in response to high BP → promotes sodium excretion (natriuresis) and vasodilation → reduces blood volume and BP.
• What role do the kidneys play in long-term BP regulation?

  They adjust sodium and water excretion based on BP levels, maintaining fluid balance via the pressure-natriuresis mechanism.
• How is hypertension defined according to UK guidelines?

  Persistently elevated blood pressure, with a clinic reading of ≥140/90 mmHg or an ambulatory/home reading of ≥135/85
• What are the categories of hypertension severity?

  • age 1 hypertension: Clinic BP ≥140/90 mmHg or home/ambulatory BP ≥135/85 mmHg.
  • Stage 2 hypertension: Clinic BP ≥160/100 mmHg or home/ambulatory BP ≥150/95 mmHg.
  • Severe hypertension: Clinic BP ≥180/120 mmHg (requires urgent assessment).
• What is primary (essential) hypertension?

  Hypertension with no identifiable cause, accounting for ~90-95% of cases. Risk factors include genetics, obesity, high salt intake, and stress.
• What is secondary hypertension?

  Hypertension due to an underlying condition such as chronic kidney disease, endocrine disorders (e.g., Cushing’s syndrome, pheochromocytoma), or renal artery stenosis.
• Why is hypertension considered a "silent killer"?

  Hypertension is often asymptomatic, leading to organ damage over time without warning signs.
• How does hypertension increase cardiovascular disease (CVD) risk?

  Hypertension increases arterial stiffness and endothelial dysfunction, promoting atherosclerosis and raising the risk of:

  • Myocardial infarction (heart attack)
  • Stroke (ischaemic and haemorrhagic)
  • Heart failure
• How does hypertension affect the brain?

  Chronic hypertension can cause:

  • Stroke (both ischaemic and haemorrhagic) due to weakened arteries.
  • Vascular dementia from reduced cerebral perfusion.
• What is hypertensive retinopathy?

  Damage to the retinal blood vessels due to prolonged hypertension, leading to blurred vision, haemorrhages, and potential blindness.
• How does hypertension contribute to kidney disease?

  High BP damages renal arteries, reducing kidney function and potentially leading to chronic kidney disease (CKD) or kidney failure.
• What is hypertensive emergency, and why is it dangerous?

  A severe BP rise (≥180/120 mmHg) causing acute organ damage, including:

  • Encephalopathy (brain swelling, confusion, seizures)
  • Acute kidney injury
  • Aortic dissection (life-threatening arterial tear)
• What are the main risk factors for hypertension?

  • Non-modifiable: Age, genetics, ethnicity, family history
  • Modifiable: Obesity, high salt intake, smoking, alcohol, physical inactivity, stress, poor diet, chronic conditions (diabetes, kidney disease)
• How does age influence the risk of hypertension?

  Blood vessels lose elasticity with age, increasing resistance and blood pressure.
• Why is family history a risk factor for hypertension?

  Genetic predisposition affects blood pressure regulation and salt sensitivity.
• How does obesity contribute to hypertension?

  Excess fat increases vascular resistance and stimulates the renin-angiotensin-aldosterone system (RAAS), leading to higher BP.
• What is the role of high salt intake in hypertension?

  Excess sodium leads to water retention, increasing blood volume and pressure.
• How does smoking increase hypertension risk?

  Nicotine causes vasoconstriction, increasing peripheral resistance and BP.
• How does alcohol consumption affect blood pressure?

  Chronic alcohol intake raises sympathetic activity, increasing BP
• How does physical inactivity contribute to hypertension?

  Reduced exercise leads to poor vascular function, increased arterial stiffness, and higher BP.
• How do chronic conditions like diabetes and kidney disease lead to hypertension?

  • Diabetes: Causes endothelial dysfunction and arterial damage.
  • Kidney disease: Impaired fluid balance and increased RAAS activation.
• What are the key lifestyle modifications to prevent hypertension?

  • Diet: Reduce salt, increase potassium, follow DASH/Mediterranean diet
  • Exercise: 150 mins/week moderate activity
  • Weight loss: Maintain a healthy BMI
  • Smoking cessation
  • Limit alcohol consumption
  • Manage stress
•  How does the DASH diet help prevent hypertension?

  Emphasises fruits, vegetables, whole grains, lean protein, and low sodium to improve vascular health.
• Why is reducing sodium intake important for hypertension prevention?

  Lower sodium intake reduces water retention and vascular resistance.
• How does potassium intake help lower blood pressure?

  Potassium helps counteract sodium’s effects and promotes vasodilation.
• What is the recommended level of physical activity to reduce hypertension risk?

  At least 150 minutes of moderate or 75 minutes of vigorous exercise per week.