Published: 18 Jun 2025

ICD9: 405.01      ICD10: I15.0      ICD11: BA00.Z

Malignant hypertension, now more accurately referred to as hypertensive emergency, is a severe and life-threatening form of high blood pressure (hypertension).
It's characterized by a sudden and dramatic increase in blood pressure that can cause damage to vital organs.

Here's a breakdown of the key aspects:

Key Characteristics:

Extremely high blood pressure: Systolic (top number) typically above 180 mmHg and/or diastolic (bottom number) above 120 mmHg. However, it's the rate of rise and associated organ damage that define the emergency, not just the specific numbers. Someone with chronically high blood pressure may tolerate these levels better than someone whose blood pressure has suddenly spiked.
End-organ damage: This is the critical difference between a hypertensive urgency and a hypertensive emergency. Damage to vital organs like the brain, heart, kidneys, or eyes is actively occurring.
Rapid onset: The blood pressure typically rises very quickly.
Requires immediate medical attention: Hypertensive emergency is a medical emergency that requires immediate treatment, usually in a hospital setting, to prevent permanent organ damage or death.

End-Organ Damage (Examples):

The elevated blood pressure causes damage to the walls of the blood vessels, which can lead to:

Brain:
Hypertensive encephalopathy: Swelling of the brain leading to headache, confusion, seizures, visual disturbances, and altered mental status.
Stroke (ischemic or hemorrhagic): Blockage or rupture of blood vessels in the brain.
Heart:
Acute myocardial infarction (heart attack): Damage to the heart muscle due to lack of blood flow.
Acute heart failure: The heart is unable to pump enough blood to meet the body's needs, leading to fluid buildup in the lungs (pulmonary edema).
Aortic dissection: A tear in the wall of the aorta, the body's largest artery.
Kidneys:
Acute kidney injury: Sudden loss of kidney function.
Eyes:
Retinopathy: Damage to the blood vessels in the retina, potentially leading to vision loss.
Pregnancy:
Eclampsia: Seizures in a pregnant woman with pre-eclampsia (high blood pressure and protein in the urine).

Causes:

Often, the cause is unknown (essential hypertension), but some contributing factors and underlying conditions include:

Uncontrolled or untreated chronic hypertension: The most common underlying cause.
Stopping blood pressure medications suddenly: Rebound hypertension.
Kidney disease (renal artery stenosis, glomerulonephritis):
Certain medications: Some medications, like decongestants, stimulants, or MAO inhibitors (when combined with certain foods/medications), can raise blood pressure.
Illegal drugs: Cocaine, amphetamines.
Pre-eclampsia/eclampsia (in pregnancy):
Pheochromocytoma: A rare tumor that produces hormones that can cause very high blood pressure.
Spinal cord injuries or tumors:

Symptoms:

Symptoms can vary depending on which organs are being affected, but common signs include:

Severe headache
Visual disturbances (blurred vision, double vision)
Chest pain
Shortness of breath
Seizures
Confusion or altered mental status
Numbness or weakness in the face, arm, or leg
Nausea and vomiting

Diagnosis:

Diagnosis involves:

Measuring blood pressure: The initial indicator.
Physical examination: Assessing for signs of organ damage.
Blood tests: To evaluate kidney function, cardiac enzymes (to check for heart damage), electrolytes, and other indicators.
Urine tests: To check for protein and other abnormalities.
Electrocardiogram (ECG): To assess heart function.
Imaging studies (CT scan, MRI): To evaluate the brain for stroke or other problems, or to look for aortic dissection.

Treatment:

Treatment focuses on rapidly but carefully lowering blood pressure to a safer level. This is usually done in an intensive care unit (ICU) setting with intravenous (IV) medications. The goal is *not* to bring the blood pressure down to normal immediately, as this can also be dangerous. Instead, the blood pressure is typically lowered gradually over several hours to avoid causing decreased blood flow to vital organs. The specific medications used and the target blood pressure will depend on the specific situation and the organ systems involved.

Prognosis:

The prognosis depends on the severity of the end-organ damage and how quickly treatment is initiated. Without prompt and effective treatment, hypertensive emergency can lead to serious complications, permanent organ damage, or death. Even with treatment, there can be long-term effects depending on the extent of the damage.

Key Differences: Hypertensive Urgency vs. Emergency

It's crucial to understand the difference between a hypertensive urgency and a hypertensive emergency:

Hypertensive Urgency: Severely elevated blood pressure (typically >180/120 mmHg) *without* evidence of acute end-organ damage. Treatment usually involves oral medications to gradually lower blood pressure over 24-48 hours. The patient can usually be managed as an outpatient with close follow-up.
Hypertensive Emergency: Severely elevated blood pressure (typically >180/120 mmHg) *with* evidence of acute end-organ damage. This is a life-threatening condition requiring immediate hospitalization and intravenous medications to rapidly (but carefully) lower blood pressure.

In summary, hypertensive emergency is a critical condition characterized by severely elevated blood pressure and acute end-organ damage. It requires immediate medical attention to prevent potentially life-threatening complications.