When Is High Blood Pressure an Emergency?

By Irmanie Hemphill, MD, FAAFP
Medically reviewed
November 12, 2021

Your blood pressure—the force of your blood as it travels through your arteries and blood vessels—can be high chronically, due to your diet, lifestyle, or genetics.

But it can also raise in an acute way: When you’re stressed, for example, your blood pressure can literally go up.

In some situations, your blood pressure can be a medical emergency.

Called a “hypertensive crisis,” these situations where your blood pressure rises too high can only be treated in an emergency room.

When is high blood pressure an emergency?

In this article, I’ll talk about high blood pressure, its symptoms and causes, and when it’s an emergency.

I’ll outline some of the damage that a hypertensive emergency can cause if it’s ignored.

And I’ll tell you when you should go to an emergency room for your symptoms.

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What is High Blood Pressure?

Blood pressure is the force of blood as it travels through your arteries and blood vessels.

The more tension there is, the higher your blood pressure reading will be.

When your arteries are healthy, blood flows more easily through your body as the resistance to blood flow is low.

But if your arteries are too narrow or stiff, the resistance to blood flow is higher.

Your heart must then work harder to pump blood through the body—increasing the blood pressure.

Blood pressure is measured using two numbers: Systolic pressure and diastolic pressure, which are represented as a fraction.

The fraction for normal blood pressure is under 120/80 mm Hg, commonly said as “120 over 80.”

Systolic refers to the first, or top, number used to calculate your blood pressure. This is the pressure in your arteries when your heart beats. 

Diastolic refers to the second, or bottom, number used to measure your blood pressure. This is the pressure in your arteries between heartbeats.

The systolic number is written over the diastolic number to give you your overall blood pressure. 

High blood pressure, or hypertension, is a common medical problem that can have negative consequences on your health if left untreated.

It can increase the risk for heart disease, heart attack, stroke, and kidney failure. It is also related to complications with dementia and sexual dysfunction.

Number ranges

For adults, A healthy blood pressure level is considered to be less than 120/80 mm Hg.

If you are seeing numbers that fluctuate higher than this, you may be diagnosed as follows:

  • Elevated blood pressure: Higher than 120/80 and up to 130/80
  • Stage 1 hypertension: 130/80 but lower than 140/90
  • Stage 2 hypertension: 140/90 or higher
  • Hypertensive emergency: Go to the ER immediately or call 9-1-1 if systolic pressure is 180 or higher and/or diastolic pressure is 120 or higher.

Both Stage 1 and Stage 2 hypertension can be treated effectively with blood pressure medications, diet, and lifestyle changes.

Your health care provider will likely recommend a combined approach between many interventions.

If you have a family history of high blood pressure, your plan may include medication even if your blood pressure seems to be stable.

In your readings match those of a hypertensive emergency, or if you’re displaying the symptoms of a hypertensive emergency, you’ll need to be treated immediately at the emergency room.

Symptoms of High Blood Pressure

High blood pressure does not always cause symptoms—which is why it can be dangerous.

It is sometimes referred to as a “silent killer” since it can reach life-threatening levels without many obvious warning signs.

If you do have signs or symptoms of high blood pressure, they most likely won’t show up until your blood pressure is very high.

The following are more likely to be signs of hypertensive crises, and include the following symptoms:

The only definitive way to know if your blood pressure is high is to have it checked regularly.

When High Blood Pressure Needs Immediate Care

Blood pressure that exceeds 180/120 always needs immediate medical care.

But you may require emergency care even if your numbers are lower, depending on your other health conditions.

Hypertensive crisis

If you experience any of the above symptoms and your blood pressure reads high, try to be still and calm and retest your numbers after five minutes.

However, if you are having chest pain, trouble breathing, or tightness in your arm, you should seek immediate medical care in an emergency department.

While high blood pressure itself does not cause dizziness, if you feel suddenly dizzy or lightheaded, especially alongside any of the other signs listed above, do not ignore it.

This can be a warning sign of stroke, which can be caused by a hypertensive crisis.

Hypertensive urgency occurs when systolic blood pressure is higher than 180 or diastolic blood pressure is higher than 120, but there are no other signs of acute organ damage.

Hypertensive emergencies occur when your systolic blood pressure is 180 or higher, and/or your diastolic blood pressure is 120 or higher and there are other symptoms indicative of organ damage.

These can both be life-threatening medical emergencies that can have severe consequences on other organs and body systems.

Pregnancy

As with many conditions, pregnancy often has different guidelines for medical care.

Blood volume can increase from 20-100% above pre-pregnancy levels, which can sometimes lead to higher blood pressure levels.

Blood pressure spikes in pregnancy are treated differently than in those who are not pregnant.

Other pregnancy complications can cause blood pressure changes, too, like pre-eclampsia, which can be life-threatening for both mother and baby.

OBGYNs and other health care providers who are part of a prenatal care team will provide care instructions relating to blood pressure, headaches, or other risk factors.

If you are pregnant and feel suddenly unwell or experience a severe headache, nosebleed, or any other symptoms of high blood pressure, seek immediate medical attention at an ER.

Risks of Hypertensive Emergency

Delaying medical care during a hypertensive emergency can lead to death or cause permanent and severe damage to organs, including the brain, heart, and kidneys.

Excessive pressure on artery walls from high blood pressure, even if just for a few minutes, can be damaging.

Stroke

High blood pressure can cause arteries that send blood to the brain to become blocked or burst, causing a stroke.

When a stroke happens, brain cells die rapidly as they are deprived of oxygen.

If a stroke is not treated within minutes, it can result in brain damage that can lead to speech problems, physical disability, and loss of other basic functions. It can also be fatal.

Heart attack

High blood pressure can damage heart health, resulting in a myocardial infarction (MI), or heart attack.

When blood pressure builds too high, it makes arteries less flexible and cuts off the flow of oxygen and blood back to the heart.

Without access to oxygen, the heart muscle gets damaged. If this continues without emergency medical intervention, it can be fatal.

Other risks

Uncontrolled or untreated hypertensive emergencies can also result in:

  • Aneurysm
  • Heart failure
  • Kidney damage
  • Damage to blood vessels in the eyes
  • Brain damage
  • Death

When to Go to the ER

High blood pressure alone, even if it’s elevated, may not be a sign of an immediate medical emergency.

However, when blood pressure is very high (180/120) or when you have related symptoms—even just general feelings of unwellness, nausea, or fatigue coupled with very high blood pressure—it is important to reassess your blood pressure and get checked out.

ER trips may be expensive and time-consuming, but not acting quickly enough can have serious consequences.

Ask your doctor for personalized guidelines to know what threshold would require an emergency room visit for you, but in general, high blood pressure with chest pain, shortness of breath, dizziness, or other symptoms of a stroke (arm weakness, numbness in one side of the body, problems speaking) constitute a medical emergency.

Emergency medical providers will determine what’s going on and provide medical care.

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How K Health Can Help

Virtual health care providers like our K Health doctors can help you manage your blood pressure health, but not during a medical emergency.

For proactive care, you can get affordable primary care right in the K Health app.

Download K to check your symptoms, explore conditions and treatments, and if needed text with a doctor in minutes. K Health’s AI-powered app is HIPAA compliant and based on 20 years of clinical data.

Frequently Asked Questions

How high can my blood pressure get without experiencing symptoms?
High blood pressure does not always cause symptoms, even when it is high enough to be a medical emergency. Checking your numbers is the only true way to know what your blood pressure is. If you have been diagnosed with high blood pressure or your doctor is concerned about your levels, you may be asked to check it at home with a blood pressure cuff, or your health care provider may use ambulatory monitoring (where you wear a device that checks your levels every 20-30 minutes throughout the day and night).
Can high blood pressure be fatal?
If your blood pressure gets extremely high, like 180/120, it can cause problems that can kill you. These can include heart attack or stroke, both of which are medical emergencies. Treatment of hypertension is designed to prevent severe levels and to promote balanced, normal blood pressure.
Will medication help during a hypertensive crisis?
You should not try to self-medicate at home during a hypertensive crisis. In an emergency room, your medical care team will treat you with medications to stabilize your blood pressure. Depending on the other symptoms involved, these could include esmolol (Brevibloc), nitroglycerin (Rectiv, Nitro-Time, others), clevidipine (Cleviprex), nitroprusside (Nitropress, Nipride RTU, others), and others, which will often be given by IV.
K Health articles are all written and reviewed by MDs, PhDs, NPs, or PharmDs and are for informational purposes only. This information does not constitute and should not be relied on for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.

Irmanie Hemphill, MD, FAAFP

Dr. Hemphill is an award winning primary care physician with an MD from Florida State University College of Medicine. She completed her residency at Halifax Medical Center.