Malignant Hypertension: Symptoms, Causes, And Treatment

Malignant hypertension is a blood pressure emergency. People who experience the symptoms need immediate medical attention. While cases of malignant hypertension are rare, they can be dangerous. Recognizing the signs and getting assistance on time are the keys to a positive outcome.

Many people confuse blood pressure spikes with malignant hypertension. If your blood pressure is high, it's not always a medical emergency. Learning about malignant hypertension can help you make the right decisions when your blood pressure goes up.

So, what is malignant hypertension, and how do you recognize it? Let's take a closer look.

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What is malignant hypertension?

Malignant hypertension is a quick, sudden, and significant increase in blood pressure. The severe rise of blood pressure leads to organ damage. It can affect the central nervous system, the cardiovascular system, and the renal system.

Normal blood pressure for an average adult is less than 120/80mm Hg (millimeters of mercury). The first number is your systolic pressure (pressure in the blood vessels while the heart is beating), while the second number is your diastolic pressure (pressure in the blood vessels while the heart relaxes between beats).

According to the new guidance of the American Heart Association, a hypertensive crisis happens when:¹

  • Systolic pressure is over 180mm Hg

  • Diastolic pressure is over 120mm Hg

  • Or both

Not every hypertensive crisis leads to malignant hypertension. Organ damage must be present for the condition to be identified as such. A quick reaction can prevent complications.

The prevalence of malignant hypertension isn't high. It affects around 0.002% of the Caucasian and 0.007% of the Afro-American population.² While the problem may develop in people with a previous history of hypertension, more than 55% of malignant hypertension cases occur without any prior diagnoses.³

Essential vs. malignant hypertension

Essential (also called primary) hypertension is high blood pressure that isn't a result of any known medical condition. For example, it could be caused by an unhealthy diet, genetics, or obesity.

Other cases of hypertension are called "secondary hypertension." High blood pressure has secondary causes, such as kidney disease or heart condition.

Malignant hypertension can be both essential and secondary.


Malignant hypertension is the most severe variation of high blood pressure. Organs generally affected by this condition are kidneys, heart, brain, and eyes. The common symptoms include:

  • Vision problems (blurred vision, sudden blindness, spots)

  • Severe headache

  • Chest pains

  • Back pain

  • Difficulty breathing

  • Reduced urination

  • Nausea

  • Vomiting

  • Weakness in legs, arms, face, and other areas

  • Mood changes and confusion

  • Seizures

  • Loss of consciousness

It can be hard to identify malignant hypertension by symptoms alone. If your blood pressure is over 180/120mm Hg, you must call 911. It is important to get your blood pressure down as soon as possible to avoid serious health consequences, but lowering the blood pressure too much and too quickly is also unsafe. Therefore, it is best to seek medical attention so you can be closely monitored.

Doctors will need to act quickly to prevent progressive organ damage and complications. The first goal is to reduce blood pressure by 25% within the first 60 minutes. If the patient is stable, they will work to get the blood pressure down to at least 160/110mm Hg within the next two to six hours.


Malignant hypertension can have many causes. While it may occur in people without previously diagnosed hypertension, it's still likely to happen to someone who has a history of high blood pressure.

Failing to take medications

People with high blood pressure issues and secondary conditions who fail to follow a prescribed treatment plan may experience malignant hypertension. It can happen if patients suddenly stop taking their medications.

Specific medications

Some medications can cause blood pressure spikes. They include birth control pills, monoamine oxidase inhibitors (MAOIs), and certain antidepressants. While these medications rarely cause malignant hypertension on their own, they can contribute to the condition when coupled with other high blood pressure triggers.

Renovascular disorders

The most common renovascular disorders are atherosclerotic renal artery stenosis (AS-RAS) and fibromuscular dysplasia (FMD). Both can lead to extreme blood pressure spikes.

Endocrine dysfunction

Hormone imbalance can lead to malignant hypertension. Common endocrine dysfunctions that can cause malignant hypertension include primary aldosteronism, Cushing's syndrome, adrenal gland tumors, systemic lupus erythematosus, and pheochromocytoma.

Illegal drugs

Such drugs as cocaine, amphetamines, and anabolic steroids can suddenly increase blood pressure.

Central nervous system disorders

Such problems as head or spine injury could also cause an increase in blood pressure that could turn into malignant hypertension.


The most common cause of malignant hypertension during pregnancy is preeclampsia which occurs in the second half of gestation. Scientists have yet to discover the cause of preeclampsia during pregnancy. Theories include poor nutrition, high body fat, and insufficient blood flow to the uterus.

Autoimmune diseases

Such diseases as systemic lupus erythematosus and rheumatoid arthritis can lead to malignant hypertension. The reason why these conditions affect blood pressure is currently unclear. However, studies have shown that people with autoimmune disorders have a significant prevalence of hypertension that affects their mortality rate.⁴

If you have any of the above conditions or issues, it's highly important to monitor your blood pressure regularly. Doctors often call high blood pressure a "silent killer" because it doesn't always cause symptoms.

Many people don't know that they have high blood pressure until they discover it during a routine doctor's visit.

You should measure your blood pressure at least twice a month if you don't have any underlying conditions to prevent unfortunate consequences. If you've had high blood pressure problems in the past, you should try to measure your blood pressure twice a day.

How to diagnose malignant hypertension

At the first signs of malignant hypertension, you need to call 911. Doctors will run tests and exams to check if you have malignant hypertension.

Physical exam

Before examining you, a doctor will ask about the history of high blood pressure, kidney disease, and heart conditions. You will also need to share which medications you are on and whether you've recently changed them.

A quick physical exam can reveal that a patient has extremely high blood pressure and possibly other concerning findings such as swelling in the lower legs, abnormal heart sounds, signs of fluid in the lungs, and changes in reflexes.

Eye exam

Since eye problems often accompany malignant hypertension, a doctor will examine your eyes for:

  • Bleeding in the retina ( in the back of your eye)

  • Blood vessel narrowing in the retina

  • Swelling of the optic nerve

They will also check for other possible problems with your retina, especially if you have vision-related symptoms.

Kidney check

The critical part of diagnosing malignant hypertension is checking for organ damage. Since kidneys are often the first to suffer, a doctor may order a urine test or a kidney ultrasound. They will likely do a blood test to check blood urea nitrogen and creatinine.

Heart check

Doctors will order blood tests to check cardiac enzymes (markers of heart damage) and perform either of the following:

  • Echocardiogram (ultrasound of the heart to get function and structure information about the heart)

  • Electrocardiogram

They are also likely to do a chest x-ray to check for lung congestion and heart enlargement.

Brain check

If you have neurological symptoms like vomiting or seizures, the doctor will check for brain dysfunction. This is done by performing a CT or MRI scan.

Diagnosing malignant hypertension as early as possible is the key to preventing serious damage. A recent study on 168 patients with malignant hypertension showed that:

  • 93% had significant brain damage

  • 82% had heart enlargement issues

  • 56% suffered from systolic dysfunction

  • 55% suffered from renal problems

With timely treatment, the renal 5-year survival rate was 90.8%.⁵

Treating malignant hypertension

The main goal of treating malignant hypertension is to lower your blood pressure quickly but safely.  If the blood pressure goes down too fast, it could lead to organ hypoperfusion (insufficient blood flow). That's why it's imperative to lower it gradually. This must be done in a hospital setting, most often in intensive care.

Doctors will give you blood pressure meds through an IV. Once the blood pressure goes down, you will continue taking the meds in oral form.

Other treatments will depend on the extent of organ damage and specific symptoms you experience. For example, if there is fluid in your lungs, doctors will prescribe diuretics (meds that help your body get rid of the fluids). You will also receive treatment to battle the causes of malignant hypertension.

You may need to stay in the hospital for several days until your blood pressure is under control.

More than 90% of patients who suffer from severe hypertension die within one year without proper treatment. Usually, it happens because of organ damage.⁶

With optimal treatment, the five-year survival rate is more than 90%.⁷ If you are diagnosed with malignant hypertension, it doesn't mean you will have non-reversible damage. Most patients recover, lead a normal life, and manage to keep their blood pressure under control.

Complications of malignant hypertension

Upon discharge from the hospital, patients should have close follow-up care. Complications of malignant hypertension can be severe. They include:

  • Coma

  • Pulmonary edema (fluid in the lungs)

  • Heart attack

  • Stroke

  • Heart failure

  • Kidney failure

  • Aortic dissection (a tear in the main aorta)

If left unchecked, all these complications could lead to death. However, with immediate treatment, it's possible to prevent complications. You will need to schedule regular checkups with your doctor and take blood pressure meds regularly.

How to prevent severe hypertension

While it's impossible to make sure you never suffer from malignant hypertension, you can lower your chances significantly by following these practices:

Take your blood pressure medication

If you have a blood pressure issue, you must keep it in check. Even if you feel fine, quitting blood pressure medication could lead to malignant hypertension. If you want to change the dosage or stop taking meds, speak to your doctor first.

Adjust your diet

A healthy diet can help lower your blood pressure. You can take advantage of Dietary Approaches to Stop Hypertension (DASH).⁸ It focuses on veggies, fruits, fish, meat, and low-fat dairy products.

Control your sodium intake

The American Heart Association recommends limiting your intake to 1,500mg a day or less. That's around ¾ a teaspoon of salt. You would also need to avoid sodium-rich sources like processed foods. Always read labels before buying products. You may be surprised to learn how many foods you usually eat have a high sodium content.

Quit smoking

Nicotine raises your blood pressure while you are smoking and for some time after you extinguish the cigarette. With other factors like stress or poor diet, smoking can cause malignant hypertension.

Manage your stress

Stress causes serious blood pressure spikes that could lead to malignant hypertension. Learn how to manage your stress levels and try to avoid stress triggers.

Lose weight

Monitor fat around your waist as it can cause high blood pressure. You can reduce your blood pressure by 0.5mm Hg for every lost pound by managing your weight.

Monitor your blood pressure

Even if you don't have any symptoms, monitor your blood pressure regularly. Contact your doctor to adjust your blood pressure medications if you notice frequent spikes.

Keep in mind that malignant hypertension may not lead to any symptoms until you sustain organ damage. That's why prevention is the key to avoiding this condition.

The lowdown

Malignant hypertension is a medical emergency that requires immediate attention. If you have a history of high blood pressure, you may be at risk for malignant hypertension. However, you are also more likely to monitor your blood pressure regularly and take action to prevent this problem.

If you've never been diagnosed with hypertension, you may still suffer from malignant hypertension. Keeping your blood pressure in check, eating a healthy diet, avoiding sodium-rich foods, and giving up bad habits are the best ways to prevent it.

If you feel that you may be at risk for malignant hypertension, speak to your doctor about it.

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