High Blood Pressure (Hypertension)

What is high blood pressure?

High blood pressure is when the force of blood pushing against your artery walls is consistently too high. This damages your arteries over time and can lead to serious complications like heart attack and stroke. “Hypertension” is another word for this common condition.

Healthcare providers call high blood pressure a “silent killer” because you usually don’t have any symptoms. So, you may not be aware that anything is wrong, but the damage is still occurring within your body.

Blood pressure (BP) is the measurement of the pressure or force of blood pushing against blood vessel walls. Your BP reading has two numbers:

• The top number is the systolic blood pressure, which measures the pressure on your artery walls when your heart beats or contracts.
• The bottom number is the diastolic blood pressure. This measures the pressure on your artery walls between beats when your heart is relaxing.

Healthcare providers measure blood pressure in millimeters of mercury (mmHg).

How do I know if I have high blood pressure?

Getting your blood pressure checked is the only way to know if it’s too high. You can do this by seeing a healthcare provider for a yearly checkup, even if you feel healthy. You won’t feel sick if you have high blood pressure. So, these checkups are crucial and can be life-saving. If your BP is above the normal range, your provider will recommend lifestyle changes and/or medications to lower your numbers.

What is considered high blood pressure?

Definitions of high blood pressure vary slightly depending on where you live. In the U.S., healthcare providers define high blood pressure (hypertension) as:

• A top number (systolic blood pressure) of at least 130 mmHg, and/or
• A bottom number (diastolic blood pressure) of at least 80 mmHg.

In Europe, healthcare providers define hypertension as:

• A top number of at least 140 mmHg, and/or
• A bottom number of at least 90 mmHg.

How common is high blood pressure?

High blood pressure is very common. It affects 47% of adults in the U.S. This equals about 116 million people. Of those, 37 million have a blood pressure of at least 140/90 mmHg.

High blood pressure caused or contributed to over 670,000 deaths in the U.S. in 2020.

The World Health Organization estimates that globally, over 1.2 billion people ages 30 to 79 have hypertension. About 2 in 3 of those individuals live in low- or middle-income countries.

What are the signs and symptoms of high blood pressure?

Usually, high blood pressure causes no signs or symptoms. That’s why healthcare providers call it a “silent killer.” You could have high blood pressure for years and not know it. In fact, the World Health Organization estimates that 46% of adults with hypertension don’t know they have it.

When your blood pressure is 180/120 mmHg or higher, you may experience symptoms like headaches, heart palpitations or nosebleeds. Blood pressure this high is a hypertensive crisis that requires immediate medical care.

What are the types of high blood pressure?

Your provider will diagnose you with one of two types of high blood pressure:

• Primary hypertension. Causes of this more common type of high blood pressure (about 90% of all adult cases in the U.S.) include aging and lifestyle factors like not getting enough exercise.
• Secondary hypertension. Causes of this type of high blood pressure include different medical conditions or a medication you’re taking.

Primary and secondary high blood pressure (hypertension) can co-exist. For example, a new secondary cause can make blood pressure that’s already high get even higher.

You might also hear about high blood pressure that comes or goes in certain situations. These hypertension types are:

• White coat hypertension: Your BP is normal at home but elevated in a healthcare setting.
• Masked hypertension: Your BP is normal in a healthcare setting but elevated at home.
• Sustained hypertension: Your BP is elevated in healthcare settings and at home.
• Nocturnal hypertension: Your BP goes up when you sleep.

What causes hypertension?

Primary hypertension doesn’t have a single, clear cause. Usually, many factors come together to cause it. Common causes include:

• Unhealthy eating patterns (including a diet high in sodium).
• Lack of physical activity.
• High consumption of beverages containing alcohol.

Secondary hypertension has at least one distinct cause that healthcare providers can identify. Common causes of secondary hypertension include:

• Certain medications, including immunosuppressants, NSAIDs and oral contraceptives (the pill).
• Kidney disease.
• Obstructive sleep apnea.
• Primary aldosteronism (Conn’s syndrome).
• Recreational drug use (including amphetamines and cocaine).
• Renal vascular diseases, which are conditions that affect blood flow in your kidneys’ arteries and veins. Renal artery stenosis is a common example.
• Tobacco use (including smoking, vaping and using smokeless tobacco).

Is high blood pressure genetic?

Researchers believe genes play a role in high blood pressure. If one or more of your close biological family members have high blood pressure, you have an increased risk of developing it, too.

What are the risk factors for high blood pressure?

Risk factors that make you more likely to have high blood pressure include:

• Having biological family members with high blood pressure, cardiovascular disease or diabetes.
• Being over age 55.
• Being Black.
• Having certain medical conditions, including chronic kidney disease, metabolic syndrome, obstructive sleep apnea or thyroid disease.
• Having overweight or obesity.
• Not getting enough exercise.
• Eating foods high in sodium.
• Smoking or using tobacco products.
• Drinking too much.

What are the complications of this condition?

Untreated hypertension may lead to serious health problems including:

• Coronary artery disease (CAD).
• Stroke.
• Heart attack.
• Peripheral artery disease.
• Kidney disease and kidney failure.
• Complications during pregnancy.
• Eye damage.
• Vascular dementia.

How is high blood pressure diagnosed?

Healthcare providers diagnose high blood pressure by measuring it with an arm cuff. Providers usually measure your blood pressure at annual checkups and other appointments.

If you have high blood pressure readings at two or more appointments, your provider may tell you that you have high blood pressure. They’ll talk to you about your medical history and lifestyle to identify possible causes.

Blood pressure categories

In 2017, the American College of Cardiology and American Heart Association issued new blood pressure guidelines. Healthcare providers in the U.S. use these when diagnosing and treating high blood pressure. The guidelines divide blood pressure readings into four categories, listed in the chart below. You have high blood pressure if you fall into the stage 1 hypertension or stage 2 hypertension categories.