Hypertension
By the end of this post you will be able to:
- Distinguish hypertensive emergency from markedly elevated blood pressure and initiate appropriate management.
- Apply a framework for managing elevated blood pressure in hospitalized patients.
- Initiate and titrate antihypertensive therapy, including first-line combination therapy, and recognize resistant hypertension.
TL;DR
What you need to know before seeing your first patient on your IM rotation with this condition
Estimated read time: 6 minutes
Note: The term “hypertensive urgency” has since been replaced by “asymptomatic markedly elevated BP” per the AHA 2024 Scientific Statement.
- Hypertensive emergency vs. markedly elevated BP:
• Hypertensive emergency: Severely elevated BP (typically ≥180/120) with acute end-organ damage — encephalopathy, acute stroke, aortic dissection, acute pulmonary edema, AKI, eclampsia, or acute retinal changes. Requires IV antihypertensives and ICU-level monitoring.
• Markedly elevated BP: BP ≥180/110 without acute end-organ damage (previously called “hypertensive urgency”). This is not an emergency — most of these patients do not need urgent pharmacotherapy. - Etiologies of markedly elevated BP in hospital: Pain or anxiety (most common), home medications not ordered or held, medication effects (NSAIDs, corticosteroids, stimulants, decongestants), withdrawal (alcohol, clonidine, benzodiazepines), volume overload or urinary retention, white-coat effect, etc.
- Tests to order: CBC, electrolytes, creatinine, troponin, urinalysis, 12-lead ECG. Consider: blood smear (for schistocytes — TMA), LDH/haptoglobin, urine drug screen, CT head if neurological symptoms.
- How to measure BP accurately: Validated automated oscillometric device. Patient seated, back supported, feet flat, arm bare and supported at heart level. 3 measurements at 1-minute intervals, average the last 2. No talking, no caffeine or exercise within 30 minutes. Correct cuff size (bladder encircling ≥75% of arm circumference).
- Treatment:
• Hypertensive emergency: IV antihypertensives (labetalol, nicardipine, or nitroglycerin depending on the specific emergency), target 20–25% BP reduction in first hour, ICU monitoring
• Markedly elevated BP: Address reversible causes first. Resume home antihypertensives if held. Oral agents (e.g., home medications) if needed. Gradual reduction over 24–48 hours — avoid rapid drops
Listen: MedicinePods
Note: These episodes were created prior to the new 2025 guidelines.
Read Around the Case
Based on Hypertension Canada 2025 Guidelines and the AHA 2024 Scientific Statement on Inpatient Hypertension Management
Estimated read time: 18 minutes
1. Hypertensive Urgency & Emergency
The AHA 2024 statement recommends retiring the term “hypertensive urgency” in favour of “markedly elevated BP” (BP ≥180/110 without acute end-organ damage). This distinction matters because the term “urgency” implies a need for urgent treatment, when in fact most of these patients do not benefit from rapid pharmacological BP reduction in the acute setting.
Hypertensive Emergency — End-Organ Damage to Look For
- Neurological: Hypertensive encephalopathy (headache, confusion, seizures, papilledema), acute ischemic or hemorrhagic stroke
- Cardiovascular: Acute aortic dissection, acute pulmonary edema / decompensated HF, acute coronary syndrome
- Renal: Acute kidney injury, thrombotic microangiopathy
- Obstetric: Eclampsia, severe pre-eclampsia
- Ophthalmological: Acute hypertensive retinopathy (flame hemorrhages, papilledema)
Management of Hypertensive Emergency
- ICU admission with continuous BP monitoring (arterial line if available)
- IV antihypertensives — choice depends on the specific emergency (see table below)
- Target: Reduce MAP by no more than 20–25% in the first hour, then to ~160/100 over 2–6 hours. Avoid precipitous drops — risk of watershed ischemia
- Exception — Aortic dissection: Target HR <60 and SBP <120 within 20 minutes (esmolol + nicardipine or nitroprusside)
2. In-Hospital Hypertension Management — The A-I-M Framework
The AHA 2024 Scientific Statement introduces the A-I-M framework for managing elevated BP in hospitalized patients. The core message: treating asymptomatic elevated inpatient BP should be the exception, not the rule.
A-I-M Framework for Inpatient BP
Is the BP measurement accurate?
Proper technique: correct cuff size, arm at heart level, patient resting 5 min, repeat measurement
What is driving the elevated BP?
Pain, anxiety, full bladder, nausea, home meds not ordered, NSAIDs, steroids, withdrawal (alcohol/clonidine), white-coat effect, delirium, etc.
Address the reversible cause first
Treat pain/anxiety/nausea, order home meds, empty bladder, stop offending agents. Re-check BP after intervention. Only escalate if BP remains elevated AND there is clinical concern.
Avoid the reflex to add PRN antihypertensives. The AHA 2024 statement highlights that PRN IV hydralazine for asymptomatic elevated BP in hospital is a common practice with no evidence of benefit and a risk of harm (hypotension, reflex tachycardia). Before ordering an antihypertensive, always ask: “Is this patient having end-organ damage, or just a high number?”
3. Chronic Hypertension Management (HC 2025)
The Hypertension Canada 2025 guidelines represent a major update with new definitions, targets, and first-line therapy recommendations.
Confirming the Diagnosis — Out-of-Office BP
HC 2025 recommends out-of-office BP measurement to confirm the diagnosis before starting lifelong therapy (unless BP ≥180/110 or there is end-organ damage):
- ABPM (gold standard): 24-hour ambulatory monitoring. Daytime average ≥130/80 confirms HTN
- HBPM: Home BP monitoring with validated device. Average of morning and evening readings over 7 days. Average ≥130/80 confirms HTN
Initial Tests to Order in Newly Diagnosed HTN
- Urinalysis — proteinuria, hematuria (renal disease screening)
- Electrolytes, creatinine, eGFR — baseline renal function, hypokalemia (aldosteronism)
- Fasting glucose or HbA1c — diabetes screening
- Fasting lipid panel — cardiovascular risk assessment
- 12-lead ECG — LVH, arrhythmia
- Urine albumin-to-creatinine ratio (ACR) — recommended in patients with diabetes or CKD
Key changes from 2020:
- New definition: Hypertension is now defined as ≥130/80 mmHg (lowered from ≥140/90)
- New target: SBP <130 mmHg for all patients (supported by SPRINT trial data)
- New first-line: Single-pill dual combination therapy (not monotherapy) — ACE inhibitor or ARB + thiazide or CCB. Single-pill combinations (SPCs) are preferred over free-dose combinations to improve adherence
- Chlorthalidone and HCTZ are now considered equivalent (based on the DCP trial)
When to Start Pharmacotherapy
- SBP ≥140 or DBP ≥90: Start pharmacotherapy in all patients
- SBP 130–139: Start pharmacotherapy if high cardiovascular risk: established CVD (CAD, HF, stroke/TIA, PAD), diabetes mellitus, chronic kidney disease, Framingham Risk Score ≥20%, or age ≥75 years
- SBP 130–139 without high CV risk: Lifestyle modifications first, reassess in 3–6 months
HC 2025 Antihypertensive Step Therapy
ACE inhibitor or ARB
+
Thiazide/thiazide-like diuretic or CCB
Single-pill combination preferred for adherence
ACE inhibitor or ARB + Thiazide + CCB
If still uncontrolled → consider resistant HTN workup
Trial Files
Battle of the Thiazides (DCP Trial)
Chlorthalidone vs. HCTZ — is one really better? Trial Files breaks down the evidence.
DASH Diet for Hypertension
The landmark DASH trial and its impact on lifestyle management of HTN.
Anti-Hypertensives to Prevent Stroke
Review of the evidence for BP-lowering in stroke prevention.
4. Resistant Hypertension
Definition: BP above target despite optimal doses of 3 antihypertensive agents from different classes (including a diuretic), or BP controlled but requiring ≥4 agents. Before diagnosing resistant HTN, rule out pseudo-resistance: medication non-adherence (most common), white-coat effect (confirm with ABPM/HBPM), suboptimal dosing, interfering substances (NSAIDs, oral contraceptives, decongestants, stimulants, excess alcohol, black licorice, high sodium intake), and improper BP measurement technique.
Secondary Causes to Screen For
- Primary aldosteronism — most common secondary cause; screen with aldosterone-to-renin ratio (ARR). Consider in resistant HTN, hypokalemia, adrenal incidentaloma
- Renal artery stenosis — renal Doppler ultrasound or CTA. Consider in young women (fibromuscular dysplasia) or older patients with atherosclerosis
- Obstructive sleep apnea — STOP-BANG questionnaire, polysomnography
- Pheochromocytoma — 24-hour urine metanephrines or plasma free metanephrines. Consider in paroxysmal HTN, palpitations, diaphoresis
- Cushing syndrome — overnight dexamethasone suppression test or 24-hour urine cortisol
- Thyroid disease — TSH
- Coarctation of the aorta — BP differential between arms, delayed femoral pulses (more common in younger patients)
Fourth-line agent: HC 2025 recommends adding spironolactone 25–50 mg daily as the preferred fourth agent for true resistant HTN. A recent JAMA 2025 trial showed that amiloride is non-inferior to spironolactone with fewer endocrine side effects, offering an alternative for patients who cannot tolerate spironolactone (gynecomastia, breast tenderness).
Is Amiloride as Good as Spironolactone?
Trial Files reviews the evidence comparing potassium-sparing diuretics for resistant HTN.
Baxdrostat in Uncontrolled & Resistant HTN
A novel aldosterone synthase inhibitor showing promise for resistant hypertension.
Note: These infographics were created prior to the new 2025 guidelines.
5. Lifestyle Modifications
HC 2025 recommends lifestyle modifications for all patients with hypertension, regardless of whether pharmacotherapy is initiated. These interventions can lower SBP by 5–15 mmHg and are additive to drug therapy.
The DASH-Sodium trial showed that combining the DASH diet with sodium restriction (<1.5 g/day) lowered SBP by up to 11.5 mmHg in hypertensive participants compared to a typical North American diet — an effect comparable to single-drug therapy. For patients reluctant to start medications, this is a powerful motivator.
Patient resource: Try giving this resource to your patients — How Do I Maintain a Healthy Blood Pressure? (Hypertension Canada)
Test Yourself
Two clinical scenarios to check your understanding
A 58-year-old man is admitted at 8 PM to the medical ward for community-acquired pneumonia. On the evening medication reconciliation, the nurse notes a BP of 192/108. He is asymptomatic — no headache, chest pain, visual changes, or dyspnea. His home medications include amlodipine 10 mg daily and perindopril 8 mg daily, neither of which was ordered on admission. His pain is well-controlled. After ensuring proper BP measurement technique, what is the most appropriate next step?
A 52-year-old woman is referred to your GIM clinic for persistently elevated BP. She is on ramipril 10 mg daily, amlodipine 10 mg daily, and HCTZ 25 mg daily. Her average home BP is 152/94. She reports good adherence and has no side effects. Her BMI is 27, she does not smoke, and she drinks 1 glass of wine per week. Labs: Na 141, K 3.2, Cr 82, eGFR 78. What is the most appropriate next step?
Reflect
A nurse pages you because a patient’s BP is 186/104. He has no symptoms. There is a PRN order for IV hydralazine 10 mg for SBP >180. Should you give it? What would you do instead?
Please do not include patient identifying details — no names, initials, dates, medical record numbers, or any detail that could identify a specific patient or encounter. Write about your reasoning, not about a real person.
Further Reading
-
Guideline
Hypertension Canada 2025 Comprehensive Guidelines for Prevention, Diagnosis, Risk Assessment, and Treatment of Hypertension in Adults and Children — Rabi et al. CMAJ 2025. -
Scientific Statement
Management of Hypertension in Hospitalized Patients — AHA 2024 Scientific Statement — Rastogi et al. Hypertension 2024. -
Landmark Trial
A Randomized Trial of Intensive versus Standard Blood-Pressure Control (SPRINT) — SPRINT Research Group. NEJM 2015;373:2103–2116. -
Patient Resource
Hypertension Canada — Guidelines, patient resources, and clinician tools for blood pressure management.