Hypertensive emergency
High BP alone is not an emergency. Look for organ damage. Emergency: IV treatment in a monitored bed, lowering MAP by no more than 25% at first. Urgency: oral tablets and follow-up.
A 50-year-old man stopped his BP tablets two months ago. He has a severe headache, blurred vision and has vomited twice. BP 236/138 on repeat. Fundoscopy shows flame haemorrhages and swollen discs. Creatinine 2.4 mg/dL (212 µmol/L).
Emergency or urgency, and how fast do you lower it?
- Repeat the BP properlyRight cuff size, after rest and pain relief, both arms.
- Look for organ damageBrain, eyes (fundi), heart, aorta, kidneys. Pregnancy.
- TestsECG, urine dipstick, creatinine, electrolytes, CBC, troponin if chest pain, pregnancy test in women.
- Emergency: IV treatment in a monitored bedSenior review. IV labetalol or GTN depending on the organ.
- Lower it slowlyMAP down by no more than 25% in the first hours, unless dissection, stroke or eclampsia rules apply.
- Urgency (no organ damage)Oral tablets, recheck, follow-up within days. No IV drugs.
- Never sublingual nifedipineSudden falls in BP can cause stroke and heart attack.
- Headache with confusion, fits or visual loss
- Papilloedema or retinal haemorrhages
- Tearing chest or back pain
- Focal neurology
- Pregnant or after delivery
- Chest pain or pulmonary oedema
- Rising creatinine
- Aortic dissection
- Hypertensive encephalopathy or PRES
- Brain haemorrhage
- Pre-eclampsia or eclampsia
- Malignant hypertension with kidney injury
- Phaeochromocytoma
- Stimulant use
| Severe high BP | Usually 180/120 or more |
| Emergency vs urgency | Emergency = new or worsening organ damage. Urgency = high BP without organ damage |
| First hours | Lower MAP by no more than 25%, then towards 160/100 over the next 2–6 hours |
| Aortic dissection | Systolic about 120 or lower within 20 minutes, pulse about 60 |
| Sublingual nifedipine | Never |
Check every dose against a current drug reference and your hospital protocol.
On this page
Emergency or urgency?
- Brain: encephalopathy, stroke, bleed
- Eyes: haemorrhages, papilloedema
- Heart: ACS, pulmonary oedema
- Aorta: dissection
- Kidneys: rising creatinine, blood and protein in urine
- Pregnancy: pre-eclampsia, eclampsia
- IV treatment in HDU
- High BP, often from missed tablets
- No symptoms of organ damage
- Oral tablets, recheck, follow-up
A high number is not an emergency. Many patients in Pakistan arrive with BP of 200/110 because they ran out of tablets or are in pain. Treat the pain, recheck, and restart oral treatment. Dropping the BP fast with IV drugs or sublingual nifedipine can cause the very stroke you are trying to prevent.
History and examination
- Symptoms: headache, vision, confusion, fits, chest or back pain, breathlessness, little urine.
- Usual BP tablets: missed, stopped, or never started?
- Pregnancy or recent delivery.
- Drugs: stimulants, decongestants, steroids, NSAIDs, sudden stop of clonidine or beta-blockers.
- Examine: BP in both arms, pulses, heart, lungs, neurological examination, fundoscopy, urine dipstick.
Investigations
| Test | Why |
|---|---|
| ECG | LVH, ischaemia |
| Urine dipstick | Blood and protein (kidney damage, pre-eclampsia) |
| Creatinine, electrolytes | Kidney injury, low potassium (consider hyperaldosteronism) |
| CBC and blood film | Haemolysis and low platelets in malignant hypertension (thrombotic microangiopathy) |
| Troponin | If chest pain |
| Chest X-ray | Pulmonary oedema, wide mediastinum |
| CT head | Neurological symptoms |
| CT aortogram | Suspected dissection |
| Pregnancy test | All women of child-bearing age |
Targets by situation
- MAP down by no more than 25% in the first hours
- Then towards 160/100 over 2–6 hours
- Then normal over 24–48 hours
- Systolic about 120 or lower within 20 minutes
- Pulse about 60
- Beta-blocker first (labetalol)
- GTN infusion
- Systolic below 140 is a common aim
- Different rules: see Stroke and TIA
- Ischaemic not lysed: usually leave unless above about 220/120
- Below 160/110 (usually aim about 135–150/80–100)
- Labetalol, oral nifedipine (not sublingual) or hydralazine
- Magnesium for fits
- see Pre-eclampsia
Drugs for hypertensive emergency
Never use sublingual nifedipine (biting a capsule) to lower BP. The fall is sudden and uncontrolled and can cause stroke, heart attack and death. This practice is still seen in Pakistan. Oral modified-release nifedipine swallowed whole is different and is used in pregnancy.
Hypertensive urgency
- Rest, treat pain and anxiety, recheck after 30–60 minutes.
- Restart the usual tablets if they were missed, or start oral treatment.
- Lower BP gradually over days, not hours.
- Follow-up within a few days. Check creatinine, potassium and urine.
Look for a cause in young patients
High BP in a patient under 40, very hard-to-control BP, or low potassium: think kidney disease, renal artery stenosis, hyperaldosteronism, phaeochromocytoma, coarctation, thyroid disease, and drugs. Refer for investigation.
Common mistakes
- Treating the number instead of the patient.
- Giving sublingual nifedipine.
- Dropping the BP to normal within an hour.
- Missing aortic dissection (check both arms).
- Missing pre-eclampsia in a woman who delivered last week.
- Not examining the fundi.
Frequently asked questions
What is the difference between hypertensive emergency and urgency?
An emergency is severe high BP with new or worsening organ damage (brain, eyes, heart, aorta, kidneys, pregnancy) and needs IV treatment in a monitored bed. Urgency is severe high BP without organ damage and is treated with oral tablets.
How fast should BP be lowered in a hypertensive emergency?
Lower the mean arterial pressure by no more than 25% in the first hours, then towards 160/100 over the next 2–6 hours. Aortic dissection and stroke have their own targets.
What is the IV labetalol dose?
20 mg IV over 2 minutes, then 20–80 mg every 10 minutes up to 300 mg, or an infusion of 1–2 mg/min.
Why is sublingual nifedipine not used?
It causes sudden, uncontrolled drops in BP that can lead to stroke, heart attack and death.
What is the first-line treatment for a hypertensive emergency?
IV treatment in a monitored bed, most often labetalol, or GTN when there is pulmonary oedema or ACS. The mean arterial pressure is lowered by no more than 25% in the first hours.
What are examples of hypertensive emergencies?
Hypertensive encephalopathy, brain haemorrhage, aortic dissection, acute pulmonary oedema, acute coronary syndrome, malignant hypertension with kidney injury, and pre-eclampsia or eclampsia.
Test yourself
Exam-style questions on this guide, from our two question banks. Choose an answer to see why each option is right or wrong.
1. A 50-year-old has BP 210/118. He has no symptoms, ran out of tablets 5 days ago, and his fundi, urine and creatinine are normal. What is the best management?
Answer: Restart oral tablets. Severe hypertension without acute organ damage is managed with oral treatment and gradual lowering over days.
- Admit to ICU: Not an emergency.
- IV labetalol infusion: No acute organ damage; IV lowering can cause harm.
- Sublingual nifedipine: Can cause sudden dangerous falls.
- IV hydralazine: Not needed.
2. A patient has BP 236/138, headache, papilloedema and a rising creatinine. How much should the BP fall in the first hour?
Answer: Mean arterial pressure by no more than 25%. In hypertensive emergency without dissection, lower MAP by no more than 25% in the first hour with IV labetalol in a monitored bed, then towards 160/100 over the next 2–6 hours.
- To normal (120/80) within an hour: Too fast; risks stroke and kidney injury.
- No lowering; observe: This is a hypertensive emergency.
- To 160/100 within 10 minutes: Too fast.
- By 50% within 30 minutes: Too fast.
3. A nurse suggests breaking a nifedipine capsule under the tongue for a BP of 220/120. What is the best response?
Answer: Decline: unsafe sudden BP fall. Sublingual immediate-release nifedipine causes unpredictable, precipitous falls in BP and is no longer used.
- Agree at half dose: Still unpredictable.
- Agree if no headache: Still unsafe.
- Agree if the patient is under 60: Age doesn't make it safe.
- Agree, it's the fastest option: Uncontrolled falls are dangerous.
4. A 50-year-old has BP 230/135 mmHg, headache, retinal haemorrhages with papilloedema and creatinine rising. How should BP be lowered?
Answer: IV labetalol, ~25% fall over hours. Hypertensive emergency (severe BP with acute target-organ damage — malignant hypertension, encephalopathy, AKI, aortic dissection, ACS, pulmonary oedema, eclampsia) needs IV therapy in a monitored setting: labetalol, nicardipine, nitroprusside or GTN. Reduce MAP by no more than 25% in the first hour, then towards 160/100 over 2–6 h, then normal over 24–48 h. Exception: aortic dissection (SBP < 120 within 20 min). Urgency without organ damage — oral drugs, gradual lowering.
- Sublingual nifedipine to normal: Sublingual nifedipine causes unpredictable falls in BP and risks stroke.
- Oral amlodipine and review next week: Oral therapy is too slow when there is organ damage.
- Reduce to 120/80 within 30 minutes: Lowering BP too fast causes cerebral and renal ischaemia.
5. A 55-year-old who ran out of his tablets has BP 200/120 mmHg with mild headache; fundi, ECG, creatinine and urine are normal and there are no neurological signs. What is the appropriate management?
Answer: Restart oral therapy and lower BP over days. Severe hypertension without acute target organ damage (hypertensive ‘urgency’) is managed with oral agents and gradual reduction over 24–48 hours to days, with close outpatient follow-up; address adherence. Hypertensive emergency: severe BP with acute organ damage (encephalopathy, stroke, ACS, acute heart failure/pulmonary oedema, aortic dissection, AKI, eclampsia, retinal haemorrhages/papilloedema) — IV agents (labetalol, nicardipine, GTN, nitroprusside) in monitored setting with target-specific reduction (e.g., MAP ≤ 25% in first hour; dissection — SBP < 120 within 20 min). Avoid sublingual nifedipine.
- IV labetalol to normalise BP within an hour: Rapid lowering without organ damage risks ischaemia.
- Sublingual nifedipine: Sublingual nifedipine causes unpredictable falls in BP.
- Admit to ICU for nitroprusside: There is no acute organ damage.
6. Which of the following directly stimulates renin release from juxtaglomerular cells?
Answer: Sympathetic stimulation through β1 receptors. Renin release rises with three signals: sympathetic β1 stimulation of JG cells, low perfusion pressure in the afferent arteriole, and low sodium chloride delivery to the macula densa. Angiotensin II and ANP inhibit renin. Beta-blockers lower renin.
- High sodium chloride at the macula densa: Low NaCl, not high, stimulates renin.
- Angiotensin II: Gives negative feedback.
- Atrial natriuretic peptide: Inhibits renin.
- Raised pressure in the afferent arteriole: High pressure inhibits renin.
7. A patient with phaeochromocytoma is being prepared for surgery. Which drug should be started first?
Answer: Phenoxybenzamine first. α-blockade (phenoxybenzamine, irreversible non-selective; or doxazosin) is started first to control blood pressure and expand volume. A β-blocker is added afterwards for tachycardia. Giving a β-blocker first leaves α-mediated vasoconstriction unopposed and can precipitate a hypertensive crisis.
- Propranolol alone: Unopposed α stimulation causes hypertensive crisis.
- Atenolol alone: Same problem.
- Adrenaline infusion: Worsens hypertension.
- Furosemide infusion: Not the first step.
References and dose sources
- ESC 2024 guidelines for elevated blood pressure and hypertension
- ACC/AHA 2017 guideline for high blood pressure in adults
- NICE NG136: Hypertension in adults
- NICE NG128
- NICE NG133
- ESC/ESH hypertension guidelines
- Labetalol dosing: Drugs.com: Labetalol dosage (see also our labetalol dose page)
- Glyceryl trinitrate (GTN) dosing: Drugs.com: Nitroglycerin dosage (see also our glyceryl trinitrate (gtn) dose page)
- Hydralazine dosing: Drugs.com: Hydralazine dosage (see also our hydralazine dose page)
- Amlodipine dosing: Drugs.com: Amlodipine dosage (see also our amlodipine dose page)
International guidance is linked where it reflects good practice. Where your hospital’s protocol differs, follow your hospital.