By Brandon Peters, MD 

 Medically reviewed by Jeffrey S. Lander, MD

An extreme form of high blood pressure is called hypertensive emergency. Hypertensive emergency is characterized by an acute, severe elevation in blood pressure, systolic blood pressure higher than 180 millimeters of mercury (mm Hg) or diastolic higher than 120 mm Hg, which is causing damage to at least one target organs, like the brain, heart, kidneys, and vessels.

Blood pressures in this high range without evidence of organ damage is termed "hypertensive urgency," a slightly less dangerous condition than hypertensive emergency.

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What Is Hypertension?

About 75 million people in the U.S.—or one in three adults—have been diagnosed with hypertension, or high blood pressure.1 The force of blood pushing against the walls of your arteries is called blood pressure. Each time you experience a heartbeat, blood is being pumped into your arteries.

Blood pressure readings consist of two types of pressures:

• Systolic blood pressure is the highest pressure and occurs when the heart beats and pumps blood.

• Diastolic blood pressure is the lower pressure and is when the heart is at rest, between beats, and the pressure falls.

Blood pressure readings use the two numbers, usually with the systolic number before the diastolic number. For example, 125/85 would have a systolic pressure of 125 mm Hg and a diastolic pressure of 85 mm Hg.

According to the American Heart Association, blood pressure is considered elevated when the systolic is 120 to 129 or higher or the diastolic is 80 or higher. Blood pressure readings above 180/120 are dangerously high and require prompt medical attention.2

If blood pressure remains high over time, it causes the heart to work harder and pump harder over time, which can lead to serious health problems like kidney failure, heart failure, heart attack, and stroke.

Hypertension usually appears with no symptoms.1 It's important to have periodic blood pressure checks from your healthcare provider to regularly monitor your blood pressure. A gauge, a stethoscope or electronic sensor, and a blood pressure cuff (called a sphygmomanometer) will be used to read your systolic and diastolic readings. Lifestyle changes and medications can reduce hypertension.

Symptoms

Understanding what is considered to be normal or abnormal blood pressure readings can be a tricky concept for many people. A scary blood pressure can result in major health consequences.

Hypertensive emergency is diagnosed when systolic blood pressure is higher than 180 mm Hg or diastolic is higher than 120 mm Hg accompanied by acute target organ damage.

A person with the onset of hypertensive emergency may express several symptoms including:3

• Headaches

• Blurred vision

• Increasing confusion

• Severe anxiety

• Nausea

• Increasing shortness of breath

Some other physical signs of hypertensive emergency include:

• Loss of vision (transient blindness)

• Seizures

• Loss of consciousness or unresponsiveness

• Rapid breathing

• Vomiting

• Swelling, including peripheral edema (swelling of the ankles)

Organ Damage Associated With Hypertensive Emergency

Generally, persistent high blood pressure can begin to affect organs, which is considered end-organ damage. To prevent this—and the potential for imminent organ failure—blood pressure must be reduced immediately.

Organ damage associated with hypertensive emergency may include:4

• Confusion or other changes in mental status

• Bleeding into the brain, resulting in a hemorrhagic stroke

• Heart failure

• Chest pain (unstable angina)

• Pulmonary edema (fluid in the lungs)

• Heart attack

• Aneurysm (aortic dissection)

• Eclampsia, which is associated with the onset of seizures that occur during pregnancy

Causes

Hypertensive emergencies can be caused by a variety of conditions such as intoxications, interactions between medications, aortic rupture, spinal cord disorders, collagen vascular disease, and even pregnancy.4

Other more common causes include:

• Stroke: Interruption of blood flow to the brain

• Heart attack: Blockage of blood flow to the heart usually resulting in the death of heart muscle

• Heart failure: The failure of proper heart function

• Kidney failure: The failure of proper kidney function

• Eclampsia: Associated with seizures that occur in pregnant women with high blood pressure, posing a threat to the health of the mother and baby

Hypertensive emergency occurs most commonly in certain populations, including among women, those with obesity, those with hypertension or coronary heart disease, those dealing with a mental illness, and those who require a high number of blood pressure medications. It's also strongly associated with patients who do not take or forget to take their blood pressure medications.4

Diagnosis

The results of hypertensive emergency occur secondary to the inability of the heart to pump blood effectively, due to blood vessels becoming inflamed and leaking fluid or blood.

There are two classifications of hypertensive emergencies:

• Hypertensive urgency is when blood pressure spikes, but there is no suspected damage to target organs. Blood pressure readings that are 180/100 or above would be considered a hypertensive urgency. With blood pressure medication, blood pressure can be brought down safely within a few hours.3

• Emergency hypertensive crisis, or emergent high blood pressure, involves extremely high blood pressure and damage to organs. Emergency hypertensive crisis is usually associated with life-threatening complications.

While it may seem that those diagnosed with high blood pressure may be easily susceptible to hypertensive emergency, it's estimated that only 1% to 3% of patients with hypertension will experience a hypertensive emergency during their lifetime.4

If you or someone you know is experiencing a severe increase in blood pressure, seek medical attention immediately.

Identifying extremely high levels of blood pressure and treating hypertensive emergency may require medical evaluation, followed by hospitalization. At a hospital, blood pressure medications can be safely administered, and routine tests can be performed to monitor blood pressure and assess any organ damage.

Some of these tests include periodic blood pressure readings, eye exams assessing swelling and bleeding, and blood and urine testing.

Treatment

Treating hypertensive emergencies may require admission into the intensive care unit (ICU). Blood pressure medication can be administered orally or through an IV, and monitoring levels to ensure a gradual and safe lowering of blood pressure can be done in the ICU. It's critical that blood pressure is not lowered too rapidly, to avoid adverse effects.

The drug and treatment options can vary depending on whether the hypertensive emergency represents urgency or emergency high blood pressure, and whether there's an association with a coexisting disease or condition. For those at high risk of emergency high blood pressure, rapid-acting medications will likely be administered in order to reduce complications, protect target organs, and improve clinical outcomes.

The goal for hypertensive emergency is to bring the blood pressure down as quickly as possible. The goal for hypertensive urgency The is to reduce the mean arterial pressure (MAP) by no more than 25% in the first 24 hours.4

For long-term treatment options, a healthcare provider may prescribe a daily oral blood pressure medication after stabilization.

Sources

Centers for Disease Control and Prevention. High blood pressure. 2019.

Aronow WS. Treatment of hypertensive emergencies. Ann Transl Med. 2017;5(Suppl 1):S5. doi:10.21037/atm.2017.03.34

Assarzadegan F, Asadollahi M, Hesami O, Aryani O, Mansouri B, Beladi moghadam N. Secondary headaches attributed to arterial hypertension. Iran J Neurol. 2013;12(3):106-10.

Benken ST. Hypertensive emergencies. Medical Issues in the ICU. 2018; 7-30.

By Brandon Peters, MD
Brandon Peters, MD, is a board-certified neurologist and sleep medicine specialist.