What are the JNC (Joint National Committee) blood pressure classification categories, treatment initiation thresholds, target blood pressure goals, and recommended first‑line antihypertensive agents?

JNC Blood Pressure Classification

Blood Pressure Categories

The JNC 7 classification defines four blood pressure categories: Normal (<120/<80 mm Hg), Prehypertension (120-139/80-89 mm Hg), Stage 1 Hypertension (140-159/90-99 mm Hg), and Stage 2 Hypertension (≥160/≥100 mm Hg). 1, 2

Specific Category Definitions

• Normal BP: Systolic <120 mm Hg AND diastolic <80 mm Hg 1, 2
• Prehypertension: Systolic 120-139 mm Hg OR diastolic 80-89 mm Hg 1, 2
• Stage 1 Hypertension: Systolic 140-159 mm Hg OR diastolic 90-99 mm Hg 1, 2
• Stage 2 Hypertension: Systolic ≥160 mm Hg OR diastolic ≥100 mm Hg 1, 2

Classification Rules

• When systolic and diastolic values fall into different categories, the higher category determines the overall classification (e.g., 160/86 mm Hg is classified as Stage 2 based on the systolic value) 2
• Diagnosis must be based on the average of ≥2 properly measured, seated readings obtained on ≥2 separate office visits 2, 3

Measurement Protocol Requirements

Proper blood pressure measurement requires the patient to be seated quietly for at least 5 minutes with back supported, feet flat on the floor, and arm supported at heart level. 4, 2

• Patients must avoid caffeine, exercise, and smoking for ≥30 minutes before measurement 2
• Use an appropriately sized cuff with bladder covering ≥80% of arm circumference 2
• Take at least 2 readings, 1 minute apart, and average them 4
• A single elevated reading is insufficient for diagnosis; multiple measurements on separate occasions are required to avoid misclassification and exclude white-coat hypertension 2

Treatment Initiation Thresholds and Goals

Prehypertension (120-139/80-89 mm Hg)

• No antihypertensive drugs unless compelling indications are present (heart failure, post-MI, diabetes, chronic kidney disease, or prior stroke) 1
• Lifestyle modifications are strongly recommended for all patients in this category 1, 3

Stage 1 Hypertension (140-159/90-99 mm Hg)

• Initiate thiazide-type diuretics for most patients without compelling indications 1
• May consider ACE inhibitors, ARBs, β-blockers, calcium channel blockers, or combinations as alternatives 1
• For patients with compelling indications, use drugs specific to those conditions plus other agents as needed 1
• Target BP goal: <140/90 mm Hg (or <130/80 mm Hg for patients with diabetes or chronic kidney disease) 3, 5

Stage 2 Hypertension (≥160/≥100 mm Hg)

• Initiate two-drug combination therapy for most patients 1, 4
• Typical combination: thiazide-type diuretic PLUS ACE inhibitor, ARB, β-blocker, or calcium channel blocker 1
• Use initial combined therapy cautiously in patients at risk for orthostatic hypotension 1
• Target BP goal: <140/90 mm Hg (or <130/80 mm Hg for patients with diabetes or chronic kidney disease) 3, 5

First-Line Antihypertensive Agents

Thiazide-type diuretics are recommended as first-line therapy for most patients with uncomplicated hypertension, either alone or combined with other drug classes. 1, 3

Drug Class Options

• Thiazide-type diuretics (e.g., hydrochlorothiazide, chlorthalidone): Preferred initial therapy for most patients 1, 6, 3
• ACE inhibitors (e.g., enalapril): First-line option, particularly for compelling indications 1, 6, 3
• Angiotensin receptor blockers (ARBs) (e.g., candesartan): First-line option, alternative to ACE inhibitors 1, 6, 3
• Calcium channel blockers (e.g., amlodipine): First-line option for most patients 1, 6, 3
• β-blockers: May be considered as first-line therapy 1

Compelling Indications for Specific Drug Classes

When compelling indications exist (heart failure, post-MI, diabetes, chronic kidney disease, prior stroke), prioritize drugs specific to those conditions, then add other agents as needed to reach target BP 1, 3

Lifestyle Modifications for All Categories

All patients, regardless of BP category, should implement lifestyle modifications including weight reduction if overweight, sodium restriction (<2.34 g/day), adequate dietary potassium (>120 mmol/day), increased aerobic physical activity (30-45 minutes daily), limited alcohol intake, smoking cessation, and adoption of the DASH diet. 1, 3

Important Clinical Considerations

Cardiovascular Risk Gradient

• CVD risk doubles with each 20/10 mm Hg increment above 115/75 mm Hg 2, 3
• Individuals who are normotensive at age 55 have a 90% lifetime risk of developing hypertension 1, 3

Two-Drug Initiation Threshold

• If BP is >20/10 mm Hg above goal, strongly consider initiating therapy with 2 agents, one of which should usually be a thiazide-type diuretic 3
• Most patients with hypertension will require ≥2 antihypertensive medications to achieve goal BP 3

Common Pitfall: White-Coat Hypertension

• White-coat hypertension affects approximately 15-20% of individuals with stage 1 hypertension 2
• Confirm diagnosis with out-of-office BP monitoring (home or ambulatory monitoring) before initiating treatment 4, 2

Updated Guidelines Context

While JNC 7 remains widely referenced, the 2017 ACC/AHA guidelines have lowered the hypertension threshold to ≥130/80 mm Hg and represent the current standard of care in the United States 1, 7, 6. However, the European Society of Cardiology/European Society of Hypertension retains the ≥140/90 mm Hg threshold 1.