What Is a Good Blood Pressure: Understanding Blood Pressure Readings

Maintaining good blood pressure is one of the most important things you can do for your heart health. That’s because high blood pressure puts you at increased risk of heart disease, including heart attack and stroke. Recent data from the Centers for Disease Control and Prevention found high blood pressure caused or contributed to 516,955 deaths in 2019.

What Is Blood Pressure?

To understand how blood pressure affects your heart, you need to know what it is and what it does. Blood pressure is the measured pressure of blood flow against the walls of your arteries. Your arteries carry oxygen-rich blood away from your heart to your tissues, organs, and other parts of your body.

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Why High Blood Pressure Is a Problem

When the pressure against your artery walls is too high, you have high blood pressure, also known as hypertension or HBP. Higher-than-normal pressure on your artery walls can damage them.

High blood pressure can cause several medical problems, including:

Heart disease

High blood pressure can contribute to atherosclerosis. That’s when plaque builds up inside your arteries. When this happens, your arteries narrow and harden, reducing blood and oxygen flow to your heart.

Along with increasing your risk of heart disease, this reduced blood flow can also cause:

  • Heart attack.
  • Heart failure.
  • Chest pain known as angina.


Because of its role in atherosclerosis, high blood pressure is also a leading cause of stroke. During a stroke, brain cells die because they aren’t getting enough oxygen. Stroke is a leading cause of death and disability. Hardened arteries can lead to ischemic stroke, which is where the arteries are unable to supply enough blood and therefore oxygen to the brain. This is the most common type of stroke. High blood pressure can also increase your risk of developing a brain aneurysm, which can lead to hemorrhagic stroke, or brain bleed.


An aneurysm is when a weakened artery wall bulges out or widens. “This can be the consequence of years of uncontrolled blood pressure which puts extra pressure on the artery walls over time,” said Thomas Morris, DO, cardiologist, UPMC Heart and Vascular Institute in Central Pa.

Symptoms depend on where an aneurysm is located and can include:

  • Rapid heart rate.
  • Dizziness or headache.
  • Low blood pressure.
  • Nausea or vomiting.
  • Clammy skin.
  • A feeling that something is not right.

An aneurysm that widens quickly or bursts can also cause shock or be fatal.

Plaque formation

Plaque — a substance made up of fat, cholesterol, and calcium — can build up in your arteries over time. Over time, this plaque build up can cause your artery to narrow and restrict blood flow to your heart. An excessive build up of plaque can lead to much more serious medical conditions such as a heart attack or stroke.

Kidney disease

High blood pressure can damage the vessels in your kidneys, reducing blood flow to them and causing kidney disease. Damaged kidneys have difficulty removing waste and extra fluid from your body. That extra fluid further increases your blood pressure and may eventually lead to kidney failure.

After diabetes, high blood pressure is the second leading cause of kidney failure, according to the National Institute of Diabetes and Digestive and Kidney Diseases.


Having hypertension in midlife is linked with dementia and cognitive decline as you age. That’s according to the National Institute of Health’s Mind Your Risks campaign.

Understanding Blood Pressure Readings

Your blood pressure reading consists of two numbers, both measured in millimeters of mercury, or mm Hg. These two numbers are:

Systolic pressure

This is pressure in your arteries when your heart beats. The systolic pressure is the first or upper number in your blood pressure reading. It’s the higher number because your arteries are under more pressure when your heart beats.

Diastolic pressure

This is the pressure between heartbeats. The diastolic pressure is the second or bottom number in your blood pressure reading. It’s the lower number because your arteries are under less pressure between heartbeats.

Blood Pressure Ranges

There are five defined categories of blood pressure, according to guidelines from the American Heart Association and the American College of Cardiology.

Many things can affect your blood pressure reading. So, which category you fall into depends on how frequently your blood pressure falls in that range. The American Heart Association recommends using an at-home blood pressure monitor to verify your blood pressure reading.

Normal blood pressure

A normal, or good blood pressure range, is when systolic pressure is less than 120 mm Hg and diastolic pressure is less than 80 mm Hg. For most adults, a normal or good blood pressure is less than 120/80 mm Hg.

Elevated blood pressure

An elevated blood pressure is when the systolic pressure ranges from 120 to 129 mm Hg. And your diastolic pressure is less than 80 mm Hg. If you have elevated blood pressure, chances are you’ll develop high blood pressure if you don’t to steps, like diet and exercise, to control it.

High blood pressure (hypertension) stage 1

This is when your systolic pressure consistently ranges from 130 to 139 mm Hg. Or your diastolic pressure consistently ranges from 80 to 89 mm Hg. If your readings fall in these ranges often, your doctor may prescribe medications to reduce your blood pressure, as well as ask you to make lifestyle changes.

High blood pressure (hypertension) stage 2

This is when your systolic pressure is often 140 mm Hg or higher, or your diastolic blood pressure is often 90 mm Hg or higher. If you fall in this category, your doctor most likely will prescribe medication to reduce your blood pressure. Lifestyle changes usually aren’t enough.

Hypertensive crisis

Hypertensive crisis needs medical attention. This is when your systolic pressure is higher than 180 mm Hg and/or your diastolic pressure is higher than 120.

If you take your blood pressure and it’s 180/120 mm Hg or higher, wait five minutes and measure it again. If it’s still that high, here’s how to tell if you should call your doctor — or call 911.

When to call your doctor

Call your doctor right away if you have a high reading but no symptoms. To help you get your blood pressure under control, they may increase your medication dosage or add a new medication.

When to call 911

You should call 911 if you have a high reading and any of these symptoms:

  • Chest pain.
  • Shortness of breath.
  • Back pain
  • Numbness/weakness.
  • Vision changes.
  • Difficulty speaking.

Why It’s Important to Get Your Blood Pressure Checked

You may not realize you have high blood pressure until you develop symptoms. The only way to know your blood pressure is to get it measured at least once a year.

You may need to get your blood pressure measured more often if you have risk factors for heart disease. Risk factors for heart disease include:

  • Obesity.
  • Smoking.
  • Diabetes.
  • A history of heart attack or stroke.
  • A family history of heart disease.
  • Being older. Your risk for high blood pressure and heart disease increases as you age.

Knowing your blood pressure can help your doctor help you get your blood pressure under control. By checking your blood pressure on a regular basis, you can keep it in check, and reduce your risk of heart disease.

Editor's Note: This article was originally published on , and was last reviewed on .

Understanding Blood Pressure Readings. American Heart Association. Link.

High Blood Pressure: Symptoms and Causes. Centers for Disease Control and Prevention. Link.

Facts About Hypertension. Centers for Disease Control and Prevention. Link.

What is an Aneurysm. American Heart Association. Link.

Hypertensive Crisis: When You Should Call 911 For High Blood Pressure. AHA. Link.

High Blood Pressure and Kidney Disease. National Institute of Diabetes and Digestive and Kidney Diseases. Link

Stroke. Centers for Disease Control and Prevention. Link.

About Heart and Vascular Institute

The UPMC Heart and Vascular Institute has long been a leader in cardiovascular care, with a rich history in clinical research and innovation. As one of the first heart transplant centers in the country and as the developer of one of the first heart-assist devices, UPMC has contributed to advancing the field of cardiovascular medicine. We strive to provide the most advanced, cutting-edge care for our patients, treating both common and complex conditions. We also offer services that seek to improve the health of our communities, including heart screenings, free clinics, and heart health education. Find an expert near you.