Hypertension Diagnosis & BP Measurement (ISH 2026)
The ISH 2026 guidelines give two levels of care: ESSENTIAL (minimum standard, low-resource settings) and OPTIMAL (high-resource). Give at least Essential care and add Optimal elements wherever possible.
Step 1 — Make sure the reading is a standardised office BP (sOBP)
Casual office readings are not valid for diagnosis — they usually overestimate BP. Check the reading was taken this way (ESSENTIAL):
- Before: no smoking, caffeine or exercise for 30 min; empty bladder; quiet room, comfortable temperature; seated and resting 3–5 min; nobody talks
- Position: back supported, feet flat, legs uncrossed, arm on table with mid-arm at heart level, arm bare
- Device: validated automated upper-arm cuff (lists at stridebp.org), or calibrated manual auscultatory device (Korotkoff 1 = SBP, 5 = DBP)
- Cuff: sized to mid-arm circumference (small cuff overestimates, large cuff underestimates)
- Protocol: 3 readings, 30–60 s (about 1 min) apart → average the last 2
OPTIMAL extras at first visit:
- Measure both arms; use the higher arm. A consistent SBP difference >10 mmHg → use the higher arm; >20 mmHg → investigate
- Standing BP if symptoms of orthostasis, age >65, diabetes or neurodegenerative disease. Orthostatic hypotension = SBP fall ≥20 and/or DBP fall ≥10 mmHg within 3 min of standing
Step 2 — Classify the office BP
Use the average of at least 2 visits (last 2 of 3 readings each visit).
| Category | Systolic (mmHg) | | Diastolic (mmHg) |
|---|
| Normal | <130 | and | <80 |
| Elevated BP | 130–139 | and/or | 80–89 |
| Grade 1 hypertension | 140–159 | and/or | 90–99 |
| Grade 2 hypertension | ≥160 | and/or | ≥100 |
"Elevated BP" is not normal — it needs clinical attention and usually treatment (see ish-htn-treatment-drug-strategy).
Step 3 — Decide how to confirm the diagnosis
| sOBP at first visit | ESSENTIAL | OPTIMAL |
|---|
| <130/80 | Re-measure annually | Re-measure annually |
| 130–159 / 80–99 | Confirm at 2–3 visits, 1–4 weeks apart | Confirm with out-of-office BP (home or ambulatory) — high chance of white-coat or masked hypertension |
| ≥160/100 | Confirm within days to weeks | Same |
Single-visit diagnosis only if sOBP ≥180/110 mmHg and there is hypertension-mediated organ damage (HMOD).
Hypertension is diagnosed when sOBP is ≥140/90 mmHg on at least 2 visits.
Step 4 — Out-of-office thresholds
| Method | Protocol | Elevated BP | Hypertension |
|---|
| Standardised office | ≥2 visits, 3 readings each, average last 2 | 130–139/80–89 | ≥140/90 |
| Standardised home (sHBPM) | 7 days (≥3 days, ≥12 readings), morning and evening, 2 readings each 1 min apart after 5 min rest; discard day 1 | 130–134/80–84 | ≥135/85 |
| 24-h ambulatory (ABPM) — 24-h average | ≥20 awake + ≥7 asleep readings, every 20–30 min | 125–129/75–79 | ≥130/80 |
| ABPM — daytime (awake) | | 130–134/80–84 | ≥135/85 |
| ABPM — night-time (asleep) | | 110–119/65–69 | ≥120/70 |
- sHBPM is the preferred main method for diagnosis and long-term monitoring (OPTIMAL)
- ABPM is preferred when home BP is not possible, office and home disagree, in children and pregnancy, suspected nocturnal hypertension, and before renal denervation. One 24-h recording may not suffice — repeat to confirm
- Pharmacy BP: threshold about 135/85; useful for screening and follow-up
- Kiosk BP: screening only, not diagnosis
- Cuffless devices and AI smartwatches: not for diagnosis or management — confirm with cuff BP
- Wrist-cuff devices: only validated ones, with arm supported and wrist at heart level
Step 5 — Identify the hypertension phenotype
| Phenotype | Definition | Action |
|---|
| White-coat hypertension | Office hypertension, normal home/ambulatory BP (10–30% of clinic patients) | Confirm with repeat office + out-of-office BP. No drugs if out-of-office BP clearly normal. Lifestyle + periodic home/ABPM (~25% develop sustained hypertension in 5 years). Consider drugs only if HMOD present, diagnosis confirmed, out-of-office BP near threshold, and other causes of organ damage excluded |
| Masked hypertension | Normal/elevated office BP, hypertension at home/ambulatory (10–30%) | Confirm with repeat office and out-of-office BP. Treat — aim to normalise out-of-office BP. CV risk close to sustained hypertension |
| Nocturnal hypertension | Night-time (asleep) average ≥120/70 on ABPM or home night-time device | One 24-h recording is not enough — repeat. Look for poor sleep and OSA; in elderly (≥80) or diabetes, consider autonomic dysfunction. Treat with long-acting drugs to control 24-h BP + salt restriction + sleep disorder management. No evidence for bedtime dosing or for treating isolated nocturnal hypertension |
| High BP variability | Common at age ≥70 | No agreed definition. Average BP remains the target; long-acting DHP-CCBs reduce variability most |
Isolated systolic hypertension is the commonest form after age 60 (also common in children and young adults). Isolated diastolic hypertension is less common and seen in younger adults.
Guardrails
- Never diagnose on a casual office reading — use the full sOBP protocol
- Never diagnose at a single visit unless ≥180/110 with organ damage
- Use the right threshold for the method — home 135/85 and 24-h ABPM 130/80 are lower than office 140/90
- Don't treat white-coat hypertension when out-of-office BP is clearly normal
- Don't miss masked hypertension — it carries near-sustained-hypertension risk and needs treatment
- Cuffless and smartwatch BP do not count for diagnosis
- Wrong cuff size is the commonest measurement error — check it every time
Related MD2SKILL skills
ish-htn-risk-assessment-workup — next step after diagnosisish-htn-treatment-drug-strategy — thresholds, targets, drugsish-htn-children, ish-htn-pregnancy — population-specific thresholds
Source
Stergiou GS, Kario K, Aristizabal D, Beheiry H, Cho MC, Colombari DSA, Itoh H, Jafar TH, Jones E, Li Y, Romero CA, Steckelings UM, Williams B. 2026 International Society of Hypertension Global Hypertension Practice Guidelines. J Hypertens. 2026;44. DOI: 10.1097/HJH.0000000000004451. Sections 2–3; Tables 3–7; Figures 1, 3.