Blood Pressure Readings Required Before Starting Antihypertensive Medication
Hypertension diagnosis requires blood pressure measurements on at least two separate occasions, with two or more readings averaged at each visit, before initiating antihypertensive therapy. 1
Confirmation Process for Diagnosis
- Initial screening: If office BP ≥130/80 mmHg is detected, take 2 additional readings at that same visit and average them 1
- Repeat measurements: Remeasure BP at 2-3 separate office visits to confirm the diagnosis before starting medication 1
- Out-of-office confirmation: Home BP monitoring (≥135/85 mmHg) or 24-hour ambulatory BP monitoring (≥130/80 mmHg) should be obtained to confirm office readings and exclude white coat hypertension 1
The ACC/AHA guidelines explicitly state that BP categories "should not be based on BP readings at a single point in time but rather should be confirmed by two or more readings (averaged) made on at least two separate occasions." 1
When to Start Medication: Stage-Specific Timing
Stage 2 Hypertension (≥160/100 mmHg or ≥140/90 mmHg)
- Start medication immediately after confirming diagnosis at 2-3 visits 1
- For BP ≥160/100 mmHg: Begin treatment without delay 1
- For BP 140-159/90-99 mmHg: Start drug treatment immediately upon confirmation 1
- Initial therapy with two antihypertensive medications is recommended for BP ≥150/90 mmHg to achieve target more effectively 1
Stage 1 Hypertension (130-139/80-89 mmHg)
High-risk patients (start medication immediately after confirmation): 1
- 10-year ASCVD risk ≥10%
- Diabetes mellitus
- Chronic kidney disease (eGFR <60 mL/min/1.73m²)
- Age ≥65 years
- Established cardiovascular disease
- Albuminuria (UACR ≥30 mg/g)
Low-risk patients (lifestyle modification first): 1
- Trial period of lifestyle interventions for 3-6 months before starting medication 1
- If BP remains elevated after this period, initiate pharmacologic therapy 1
- The ACC/AHA guidelines recommend 3 months of lifestyle modification 1
- ESH/ISH guidelines suggest several months, while ASH/ISH recommends 6-12 months 1
Elevated BP (120-129/<80 mmHg)
Critical Measurement Technique Requirements
Accurate BP measurement is essential to avoid over-diagnosis. Common errors that falsely elevate readings include: 1
- Incorrect cuff size (too small)
- Cuff over clothing
- Unsupported arm
- Full bladder
- Crossed or unsupported legs
- Conversation during measurement
Use validated automated devices with proper technique: patient seated after 5 minutes rest, appropriate cuff size on bare arm, arm supported at heart level, back and feet supported, legs uncrossed, empty bladder, no talking. 1
Special Populations
Diabetes Patients
- For BP between 130/80-150/90 mmHg: May begin with single agent 1
- For BP ≥150/90 mmHg: Start with two medications from different classes 1
- ACE inhibitors or ARBs are first-line if albuminuria present (UACR ≥30 mg/g) 1
Elderly (≥80 years)
- Threshold for treatment: SBP ≥160 mmHg 1
- May consider monotherapy initially 1
- Individualize based on frailty status 1
Timeline to Achieve BP Control
- Target achievement: within 3 months of initiating or adjusting therapy 1, 2
- Goal: Reduce BP by at least 20/10 mmHg, ideally to <130/80 mmHg 1, 2
- Follow-up visits every 1 month until BP controlled, then every 3-6 months 3
- For dose titration: reassess every 4-6 weeks 3
Common Pitfalls to Avoid
- Do not diagnose hypertension on a single visit: This leads to over-diagnosis and unnecessary treatment 1
- Do not delay treatment in Stage 2 hypertension: Immediate initiation is indicated after confirmation 1
- Do not use monotherapy for BP ≥150/90 mmHg: Two-drug combinations are more effective 1
- Do not skip out-of-office BP confirmation: This identifies white coat hypertension (office BP ≥130/80 but home BP <130/80) and prevents overtreatment 1