--- title: Hypertensive crisis description: What a hypertensive crisis is, how it differs from simply very high blood pressure, which organs are harmed, how it is recognised and treated, why blood pressure is not lowered too fast, and when to call an ambulance. type: disease aliases: - hypertensive emergency - acute severe hypertension sources: - tier: guideline org: minzdrav-rf title: Артериальная гипертензия у взрослых year: 2024 doi: 10.15829/1560-4071-2024-6117 url: https://cr.minzdrav.gov.ru/view-cr/62_3 - tier: guideline org: nice title: 'Hypertension in adults: diagnosis and management (NG136)' year: 2026 url: https://www.nice.org.uk/guidance/ng136 - tier: reference org: msd-manuals title: Hypertensive Emergencies (Acute Severe Hypertension) year: 2025 url: https://www.msdmanuals.com/professional/cardiovascular-disorders/hypertension/hypertensive-emergencies - tier: reference org: statpearls title: Hypertensive Crisis year: 2026 url: https://pubmed.ncbi.nlm.nih.gov/29939523/ sources_checked: 2026-10-13 review: null --- A hypertensive crisis is a condition in which a marked rise in blood pressure comes with acute damage to target organs; it is often life-threatening and needs immediate skilled care. The organs mainly affected are the brain, the heart and blood vessels, the kidneys and the retina of the eye. A crisis is defined by organ damage, not by a single reading on the blood pressure monitor: for how severe the damage is, the speed and size of the rise can matter as much as the level itself. The Russian Ministry of Health guideline does not call very high blood pressure without organ damage a crisis. For raised blood pressure in general, see the article on [hypertension](../hypertension/).

The diagram shows the heart, the aorta and the organs harmed in a hypertensive crisis: the brain, the eyes, the heart, the aorta and the kidneys. Here blood pressure is in the usual range and the organs are not damaged.

In a hypertensive crisis a marked rise in blood pressure comes with acute damage to target organs. The marks show what this damage can be: swelling of the brain (hypertensive encephalopathy) or stroke, bleeding in the retina and swelling of the optic disc, ischaemia of the heart and acute heart failure, aortic dissection, and acute kidney injury. For clarity, all of them are shown on one diagram.

## Why it happens The brain is a good example of how very high blood pressure damages organs. Normally, when blood pressure rises, the blood vessels of the brain narrow and keep the blood supply steady. With blood pressure that is too high, this protection is thought to fail: the vessels widen, the pressure reaches the tiniest vessels, fluid leaks into the brain tissue and the brain swells — this is hypertensive encephalopathy. People who have had high blood pressure for a long time tolerate high readings better than people whose blood pressure used to be normal. The risk of a crisis is higher if prescribed blood pressure treatment is not taken, and in secondary hypertension, when another disease raises blood pressure. Sometimes a person does not know about their high blood pressure before the crisis: some people who come to the emergency department with a crisis have never been diagnosed with hypertension. The Russian Ministry of Health guideline (2024) defines a hypertensive crisis as a condition in which a marked rise in BP is associated with acute hypertension-mediated organ damage (HMOD), often life-threatening, that requires immediate action to lower BP, usually with intravenous therapy. In the English-language literature, "hypertensive crisis" is the umbrella term for a severe, acute elevation in BP: with acute HMOD it is a hypertensive emergency, without it a hypertensive urgency. The Russian guideline no longer recommends the term "uncomplicated hypertensive crisis"; it uses "failure to reach target BP" instead. Typical presentations of a crisis in the Russian guideline: malignant hypertension (severe hypertension with haemorrhages and/or optic disc swelling on fundoscopy, microangiopathy and disseminated intravascular coagulation, which can lead to encephalopathy, acute heart failure and acute worsening of kidney function); severe hypertension with aortic dissection, acute myocardial ischaemia or acute heart failure; a sudden rise in BP with phaeochromocytoma associated with HMOD; and severe hypertension or pre-eclampsia in pregnancy. NICE defines accelerated (malignant) hypertension as a severe increase in BP with signs of retinal haemorrhage and/or papilloedema, usually associated with new or progressive target organ damage. Hypertensive encephalopathy may involve a failure of cerebral autoregulation: above a certain mean arterial pressure (lower in people who were previously normotensive) the cerebral vessels dilate instead of constricting, the pressure is transmitted to the capillary bed, plasma leaks into the brain and cerebral oedema develops, including papilloedema. Non-adherence to antihypertensive treatment increases the risk; a crisis is more common in secondary than in essential hypertension. ## Symptoms The signs of a crisis depend on which organ is affected. When the brain is affected, problems appear that change quickly: confusion, temporary loss of sight, weakness or numbness of one side of the body, seizures. When the heart is affected: chest pain and shortness of breath. Damage to the kidneys may cause no symptoms. Aortic dissection has its own signs; see the article on [aortic dissection](../aortic-dissection/). Very high blood pressure without organ damage often causes no symptoms, or only vague ones that do not point to organ damage. According to the MSD Manual, the most common cause of such a rise is anxiety; only a doctor can tell it apart from a crisis. Central nervous system: rapidly changing neurological abnormalities — confusion, transient cortical blindness, hemiparesis, hemisensory deficits, seizures; cardiovascular: chest pain and dyspnoea; renal involvement may be asymptomatic, although severe azotaemia from advanced kidney failure may cause lethargy or nausea. Global cerebral deficits (confusion, obtundation, coma), with or without focal deficits, suggest encephalopathy; focal deficits with a normal mental state suggest stroke. NICE refers people for same-day specialist assessment if they have a clinic BP of 180/120 mm Hg and higher with signs of retinal haemorrhage or papilloedema, or with life-threatening symptoms such as new-onset confusion, chest pain, signs of heart failure or acute kidney injury. Thresholds such as 180/120 mm Hg are not uniform and rest on convention; the rate of rise may matter even more than the level. ## How it is diagnosed The doctor looks for signs of organ damage: checks the nervous system, looks at the back of the eye and listens to the heart and lungs. In hospital, everyone with a crisis quickly has an ECG, blood and urine tests and an eye examination; women of childbearing age have a pregnancy test. Depending on the situation, a troponin test, chest X-ray, echocardiography, CT of the aorta, CT or MRI of the brain and kidney ultrasound are added. If blood pressure is very high but there are no signs of organ damage, the ambulance doctor measures it several times at rest to make sure the rise is sustained. After a first crisis, its cause is always looked for, including diseases that raise blood pressure. Russian guideline: an ECG for every patient with a crisis within 15 minutes of admission; routinely, fundoscopy and blood and urine tests to detect HMOD, and hCG in women of childbearing age; when indicated, troponins, NT-proBNP, imaging of the heart, aorta, brain and kidneys, and a urine drug screen. According to MSD, jugular venous distension, basal lung crackles and a third heart sound suggest pulmonary oedema, and asymmetry of pulses between the arms suggests aortic dissection; severe retinopathy is usually present with encephalopathy. According to NICE, in people with BP of 180/120 mm Hg or higher without reasons for same-day referral, investigations for target organ damage are done as soon as possible: if damage is found, starting antihypertensive treatment immediately is considered; if not, the diagnosis is confirmed by repeat clinic measurement or by ambulatory (or home) monitoring. In everyone with a first-diagnosed crisis, the cause of the raised BP must be found, including secondary hypertension. ## How it is treated A crisis with organ damage is treated in hospital, usually in an intensive care unit. Blood pressure is lowered with medicines given into a vein: they act briefly, so the doctor can control the fall precisely. Tablets are not suitable for starting treatment: it is unpredictable when they will start to work. Lowering starts at once, but in a controlled way and not down to normal: a fast, uncontrolled fall is dangerous and can cause complications, such as too little blood reaching the brain and heart. The doctor decides how far and how fast to lower blood pressure according to which organ is affected. In a stroke, whether to lower blood pressure and by how much is decided together with a neurologist: lowering it too fast can make the lack of blood to the brain worse. If blood pressure is very high but no organ is damaged, it does not need to be lowered urgently: it is brought down gradually, with tablets, under a doctor's supervision. Without timely treatment the outlook in a crisis with organ damage is much worse, and timely treatment has clearly improved outcomes. After a crisis the risk stays high: doctors look for the cause, choose long-term treatment, and the person is then followed up by a specialist for a long time. In a crisis, an intravenous drug with a short half-life is considered best, so that treatment can be adjusted promptly to changes in BP; rapid uncontrolled lowering of BP is not recommended because it can lead to complications. According to MSD and StatPearls, oral drugs are not indicated for initial treatment: their onset is variable and they are difficult to titrate. Achieving "normal" BP in the acute setting is neither necessary nor advisable. The choice of drug and the speed and degree of lowering depend on the organ affected; no figures are given here. The Russian guideline recommends immediate BP lowering in acute coronary syndrome, cardiogenic pulmonary oedema, aortic dissection, eclampsia and severe pre-eclampsia or HELLP syndrome, and in hypertensive encephalopathy. In acute stroke, whether and how far to lower BP is decided individually together with a neurologist, because excessive or rapid lowering can worsen cerebral ischaemia. With a marked rise in BP without acute HMOD, immediate lowering is not needed: BP is lowered in the outpatient setting with oral drugs following the standard algorithm, with closer checks on adherence. Patients who have had a crisis are a high-risk group and are screened for secondary hypertension; they are discharged once BP is at a safe, stable level on oral treatment, followed by long-term regular specialist follow-up. ## When to call an ambulance A hypertensive crisis is often life-threatening and needs immediate care. Call your local emergency number (112 in the EU, 911 in the US and Canada, 999 in the UK) if, with high blood pressure, you develop chest pain or severe shortness of breath, confusion, seizures, sudden loss of sight, or weakness or numbness of one side of the body. Also call an ambulance for very high blood pressure during pregnancy: it is treated as a hypertensive crisis and needs urgent admission to hospital. If blood pressure is very high but you feel no symptoms, do not try to bring it down sharply on your own: the doctor chooses the treatment, so see your doctor soon.