Summarize in exam approachable way
Hypertension — Exam-Ready Summary
Definition & Classification
| Type | Key Point |
|---|---|
| Essential (Primary) | Unknown cause; 90% of all hypertension cases |
| Secondary | Known cause (kidney disease, adrenal tumours, coarctation of aorta, toxemia of pregnancy); accounts for ≤10% |
India definition: SBP ≥140 mmHg OR DBP ≥90 mmHg OR currently on antihypertensive medication
Magnitude of the Problem
- Global prevalence: ~1.13 billion; kills 10 million/year
- Overall adult prevalence: 30–40% (age-standardized: 24% men, 20% women)
- Prevalence >60% in people aged >60 years
- Elevated BP causes ~10 million deaths and >200 million DALYs annually
- DALYs have ↑40% since 1990 despite advances in treatment
- SBP ≥140 mmHg accounts for most of the burden
- Top causes of SBP-related deaths: IHD (4.9M) > Haemorrhagic stroke (2M) > Ischaemic stroke (1.5M)
"Rule of Halves" (Classic Exam Favourite)
Hypertension is an "iceberg disease" — from the total hypertensive pool:
All hypertensives
→ ~½ are Diagnosed
→ ~½ of those are Treated
→ ~½ of those are Adequately treated
In developing countries, the proportion adequately treated is even lower.
Prevalence in India (NFHS-5)
| Women | Men | |
|---|---|---|
| Overall HTN | 21% | 24% |
| Pre-hypertensive | 39% | 49% |
| On medication (BP controlled) | 1% | 1% |
- Highest in Sikkim (women 35%; men 42%)
- Southern states have higher prevalence than national average
- Higher among Sikhs > Christians > other religions
- 40% of obese men and 28% of obese women are hypertensive
"Tracking" of Blood Pressure
- BP levels in childhood tend to persist ("track") into adulthood
- High BP in childhood → likely high BP as adult
- Useful to identify high-risk children and adolescents early
Risk Factors
🔒 Non-Modifiable
| Factor | Key Point |
|---|---|
| Age | BP rises with age; most significant risk factor |
| Sex | Men > women in middle age; post-menopausal women may catch up or surpass |
| Genetics | Polygenic inheritance; monozygotic twins more concordant than dizygotic; children of 2 hypertensive parents have 45% risk vs 3% if both parents normotensive |
| Ethnicity | Black communities have higher BP than other groups |
✏️ Modifiable
| Factor | Key Point |
|---|---|
| Obesity | Greater weight gain → greater BP; central obesity (↑waist:hip ratio) is key |
| Salt intake | High salt (7–8 g/day) ↑BP; low sodium ↓BP; Japan (high Na) vs primitive societies (low Na) |
| Potassium | Antagonizes sodium; lowers BP in mild-moderate hypertensives |
| Saturated fat | ↑BP and serum cholesterol |
| Dietary fibre | Inversely related to CHD and HTN risk |
| Alcohol | High intake ↑SBP > DBP; reversible with abstinence |
| Heart rate | Higher in hypertensives; suggests sympathetic overactivity |
| Physical inactivity | Sedentary lifestyle → ↑BP indirectly via weight |
| Stress | Psychosocial factors → catecholamine release → ↑BP |
| Socio-economic status | Post-transitional societies: HTN higher in low SES; Pre-transitional: higher in high SES |
| OCP | Most common cause of secondary HTN (oestrogen component) |
Prevention of Hypertension
1. Primary Prevention
a) Population Strategy
- Target: Whole community, regardless of individual risk
- Rationale: Small ↓ in average BP → large ↓ in cardiovascular events (Rose's strategy)
- Interventions (non-pharmacological):
- Nutrition: ↓salt to <5 g/day, moderate fat, avoid excess alcohol, restrict energy
- Weight reduction: BMI 18.5–24.9
- Exercise promotion: Regular physical activity
- Behavioural change: Stress reduction, stop smoking, yoga, meditation
- Health education
- Self-care: Teach patients to measure and log their own BP
b) High-Risk Strategy
- Target: Individuals with very high risk (family history, childhood tracking)
- Goal: Prevent BP reaching levels where treatment is needed
2. Secondary Prevention (Detect & Control)
| Component | Key Points |
|---|---|
| Early Case Detection | Screening the population; must be linked to follow-up/treatment — screening alone is useless |
| Treatment | Aim: BP <140/90, ideally 120/80 mmHg; treat the BP (not the cause in essential HTN) |
| Patient Compliance | Treatment is lifelong; compliance = taking meds + diet + lifestyle as prescribed; improve via education |
Lifestyle Modifications — TABLE 2 (High-Yield)
| Modification | Recommendation | SBP Reduction |
|---|---|---|
| Weight reduction | BMI 18.5–24.9 | 5–20 mmHg/10 kg |
| DASH diet | Fruits, vegetables, low-fat dairy, ↓saturated fat | 8–14 mmHg |
| Dietary sodium ↓ | ≤100 mEq/day (2.4 g Na or 6 g NaCl) | 2–8 mmHg |
| Physical activity | Aerobic, ≥30 min/day, most days | 4–9 mmHg |
| Alcohol moderation | ≤2 drinks/day (men); ≤1 drink/day (women) | 2–4 mmHg |
Stop smoking for overall CVD risk reduction (no direct BP effect listed)
DASH = Dietary Approaches to Stop Hypertension
Quick Exam Mnemonics
"SOAP-HE" for modifiable risk factors:
- Salt, Obesity, Alcohol, Physical inactivity, Heart rate (stress), Environment/SES
"Rule of Halves" = diagnosed / treated / adequately treated are each ~½ of the previous group
"3 vs 45" = children with 0 hypertensive parents have 3% risk; with 2 hypertensive parents → 45% risk
This is a shared conversation. Sign in to Orris to start your own chat.