High Blood Pressure (Hypertension): A Guide to Symptoms, Causes and Tests

Learn the risk factors for high blood pressure, testing options and why it is known as the silent killer

Kimberly Hayes,

Updated February 24, 2026

AARP

Reviewed by

Merle Myerson, M.D.

Comments

En español

Published June 03, 2024

/ Updated February 24, 2026

a man getting his blood pressure checked at the doctor's office

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High Blood Pressure Guide

A staggering three-quarters of Americans ages 65 to 74 have high blood pressure, otherwise known as hypertension, putting them at increased risk for stroke, heart attack, heart failure and dementia. Men tend to have higher blood pressure rates in their younger years, but women catch up around the time of menopause.

Hypertension increases with age. The American Heart Association’s (AHA) 2026 “Heart Disease and Stroke Statistics” report shows that while rates are relatively low in people ages 20 to 34 (30 percent for men and 16.6 percent for women), rates rise to 81.8 percent for women after age 75. Rates go up to around 70 percent for men after age 65. (See chart below.)

These alarming rates are even higher for people of color, especially for African Americans. Hypertension prevalence across all ages is higher among non-Hispanic Black adults (62.3 percent for men and 59.2 percent for women) than non-Hispanic whites (50.4 percent for men and 42.2 percent for women).

What causes high blood pressure?

“The main cause of high blood pressure is aging blood vessels,” says Dr. Jordana Cohen, associate professor in the Renal-Electrolyte and Hypertension division at the Hospital of the University of Pennsylvania. She is also past chair of the AHA’s Hypertension Science Committee.

Blood vessels tend to stiffen with age and become less flexible, which can raise pressure inside them. However, studies have found that there are populations of older people who don’t have high blood pressure. For example, the remote South American Yanomami tribe lives in near-total isolation in the rainforests in southern Venezuela and northern Brazil. Its members eat very little salt and fat and have a diet high in plantains, fruit and meat, and their blood pressure doesn’t increase with age.

Research suggests this may be related to their lower salt intake and their high potassium intake, Cohen says. They also have less exposure to modern-day risk factors such as pollution, stress and other diseases that are prevalent in our society, like diabetes, heart disease and kidney disease, all of which contribute to high blood pressure, Cohen adds.

Understanding a blood pressure reading

Blood pressure is measured in stages, with a normal range below 120/80 mm Hg (millimeters of mercury, a standard unit for measuring pressure). The top number — the systolic— is the pressure in your arteries when your heart beats and pushes blood through them, bringing it to each part of your body. The bottom number — the diastolic — measures the pressure in your arteries when the blood is flowing back to the heart through the veins.

The stages at or above 120/80 mm Hg include elevated stage 1 hypertension and stage 2 hypertension. (See blood pressure ranges table.) A severely elevated blood pressure of 180/120 mm Hg or greater could be a hypertensive emergency and could require guidance from your doctor or, in some cases, emergency care.

“The top number is what’s mostly considered our biggest indicator of risk,” Dr. Jordana Cohen says. It also tends to be the most responsive to treatment.

The bottom number tends to be higher in younger people and decreases with age. Older patients can see a very wide split between their top and bottom numbers, which can be concerning, Cohen says, especially if the bottom number gets too low. In this case, people may feel lightheaded, which can lead to falls, and the risk of kidney problems can increase.

“This is something that I see in my much older patients in their 80s, 90s and 100s,” Cohen says.

What are the symptoms of high blood pressure?

Most people with hypertension shouldn’t expect to experience symptoms from high blood pressure. This is why it is called the silent killer.

“If your expectation is that you’re going to feel it, then you’re going to be somebody who’s missing it 90 percent of the time,” Cohen says.

Generally, people will not feel any symptoms of high blood pressure unless their blood pressure is severely elevated. This occurs when a patient’s underlying high blood pressure has accelerated to 180/120 mm Hg or higher and is damaging vital organs, including the brain, heart, kidneys or eyes. In this scenario, the person could face additional symptoms, including sudden headache, blurred vision or vomiting, and should seek emergency medical assistance.

It’s important to note that people with poorly controlled blood pressure could have readings in this higher range, but as long as they are not having other symptoms, it may not be an emergency. However, they still should follow up with their doctor within a couple of days.

While patients may assume a blood pressure measurement at a doctor’s office is the most accurate, that’s not always the case.

To get a good blood pressure reading, it’s recommended that the person sit in a quiet environment with their feet flat on the floor and their arms held at the level of their heart (upper chest). The arms can be placed on a table or desk in front of them.

This ideal scenario may not always be how someone is positioned at the doctor’s office. Couple that with the stress of a doctor’s visit and it’s easy to see how readings may not be 100 percent accurate.

White coat hypertension and masked hypertension

According to the Cleveland Clinic, between 15 and 30 percent of people have so-called white coat hypertension, which means their blood pressure is higher at a health care provider’s office but normal at home. Estimates vary, however, with some research saying up to 50 percent or more of people have white coat hypertension.

But it’s important not to completely discount these higher doctor’s office readings. “I think white coat can be used to deny high blood pressure,” says Dr. Beverly Green, a senior investigator at the Kaiser Permanente Washington Health Research Institute. “There’s literature showing that people with white coat hypertension are at higher risk of eventually getting high blood pressure.”

At the opposite end of white coat hypertension is masked hypertension. The prevalence of masked hypertension varies, but approximately 10 to 20 percent of people have this condition, which occurs when blood pressure is normal in the doctor’s office but high in everyday life.

This can happen among people who typically smoke but avoid doing so right before a doctor’s visit. People with sleep apnea may also be at risk, Cohen says.

The importance of home blood pressure monitoring

With home monitoring, patients can hopefully control their environment and take their readings at ideal times. (See guidelines on checking your blood pressure at home at the end of this article.)

It’s important to make sure you are using an accurate device. More than two-thirds of the devices on the market right now are not, Cohen says. Check out the best blood pressure monitors we’ve tested for accuracy, comfort, ease of use and more.

Of course, it’s still important to get your blood pressure checked at your doctor’s office and to discuss the readings you take at home with them. Some providers use an automated office blood pressure machine, which provides multiple readings over a series of intervals. This can be used in a quiet room without a medical professional present, hopefully reducing white coat hypertension.

If you monitor your blood pressure at home and your machine records past readings, you can bring it in for your doctor to review. Or make a chart of your readings, including the time of day they were taken, to share with your provider.

Ambulatory blood pressure monitoring

Some patients are referred for ambulatory blood pressure monitoring, in which your blood pressure is continuously measured for 24 hours as you go about your daily life, even while you sleep. Your doctor will calculate the average blood pressure for daytime and nighttime readings and also look at the range, how often readings are high or low, and if there is a “dip,” meaning a lowering of blood pressure during nighttime hours, which is normal.

Ambulatory monitoring can be used for patients who have had high blood pressure readings but haven’t yet started treatment, need changes to their medications, have blood pressure that is not responding to medications, or have felt dizzy or have had fainting episodes.

Green has used ambulatory monitoring herself and, to her surprise, found that she had high blood pressure during the workday. “I wouldn’t have known that I had high blood pressure while at work, and there are a lot of people walking around just like that whose hypertension wouldn’t have been caught otherwise,” Green says.

High Blood Pressure and Dementia

The recent AHA/American College of Cardiology blood pressure guidelines state that in adults with hypertension, a goal of less than 130 mm HG systolic blood pressure is recommended to prevent mild cognitive impairment and dementia.

It’s been shown that both home and ambulatory monitors do a better job of predicting heart attacks, strokes and death because they capture the variability in average blood pressure much better than occasional blood pressure readings in the doctor’s office, Green says.

Unfortunately, ambulatory monitoring can be difficult for some patients to access, as it is more commonly found in specialized hypertension clinics and is not available in every doctor’s office, Cohen says. But studies have shown that home blood pressure monitoring with a store-bought monitor is a good surrogate for ambulatory monitoring. “It’s not expensive, and everyone can do it.”

Read more about home blood pressure monitoring and see our guide to home blood pressure monitors.

The following high blood pressure guide shows you the science behind high blood pressure and the various factors that can play a role in high blood pressure’s causes and symptoms:

High blood pressure myths

Blood pressure myths about types of salt, wine intake and medications persist in popular culture. Here’s a look at six blood pressure myths, plus tips you can use to maintain a healthy blood pressure.

Read more about high blood pressure myths.

Alcohol and high blood pressure

Research has traditionally shown that heavy drinking raises your risk for high blood pressure, but now experts believe even light to moderate drinking can carry risks.

Read more about alcohol and high blood pressure.

Smoking and high blood pressure

While smoking is not a primary risk factor for high blood pressure, the habit can damage blood vessels, contributing to plaque buildup and hardening arteries. Nicotine, the addictive chemical compound in cigarettes, can also increase blood pressure.

Read more about smoking and high blood pressure.

Anxiety, stress and high blood pressure

Stress can trigger blood pressure to rise in the short term, and if that happens frequently enough, it could damage the blood vessels, heart and kidneys, similar to what happens in people with long-term hypertension. But that’s different from saying stress or anxiety themselves produce high blood pressure.

Read more about the links between anxiety, stress and high blood pressure.

Is high blood pressure genetic?

A May 2024 study in Nature Genetics analyzed the genes of more than 1 million people of European heritage and uncovered some 113 gene variants associated with high blood pressure. While you can’t change your genes, there are lifestyle changes you can make that will likely have a much bigger impact on your risk for high blood pressure.

Read more about high blood pressure and genetics.

Medications that cause high blood pressure

Pain and migraine medicines, decongestants, corticosteroids and some herbal supplements are all examples of pills that can raise your blood pressure. A 2021 study revealed that 18.5 percent of adults with hypertension were taking one or more of these medications.

Surprising causes of high blood pressure

While salt is one of the most associated risk factors for high blood pressure, a handful of unsuspected foods, habits and health issues can play a role too.

Hypertension headache

A common myth persists among some patients who think they can sense their blood pressure is creeping up because they’ve started getting headaches. However, research shows the link between high blood pressure and headaches is shaky, particularly for mild and moderate high blood pressure.

Read more about high blood pressure headaches.

Todd Detwiler

How to properly measure your blood pressure at home

Do’s:

Make sure your blood pressure monitor has been validated at validatebp.org. Confirm that the cuff fits by measuring around your upper arm and choosing a monitor with the correct cuff size. Wrist and finger monitors are not recommended because of less reliable readings.
Be in a quiet room, avoid conversation and relax for three to five minutes before taking your blood pressure.
Make sure that you’re positioned correctly. Sit at a kitchen table or a desk where your feet are flat on the floor, your back is supported and your arms are resting on the table at the level of your heart.
Put the cuff on your bare arm. If you must push your sleeve up, make sure it is loose-fitting. A tight sleeve could create a tourniquet effect and raise your blood pressure.
Empty your bladder before a reading. Having a full bladder can raise your blood pressure, according to the American Medical Association.
Take your blood pressure twice. People often get a surge of adrenaline when they first take the reading.
Record your blood pressure measurements, along with the time of day you took them, and discuss these results with your doctor. The AHA offers a printable blood pressure log.

Don’ts:

Smoke, eat or drink coffee or other caffeinated beverages or exercise at least 30 minutes before taking your blood pressure.

“We usually recommend checking two back-to-back readings about 30 seconds to a minute apart in the morning, before taking medications … and two back-to-back readings in the evening before going to bed, at least an hour after dinner, for a minimum of three days per month,” says Cohen. “That’s the minimum needed to get a really accurate reading.”

Doing this series of checks once a month is recommended for people currently being treated with blood pressure medication. If your blood pressure is borderline, three days of monitoring every two to three months is recommended, Cohen says.

While these are general guidelines, you should discuss how frequently to take your blood pressure with your doctor, based on your individual medical needs.

The website Targetbp.org offers additional tools and guides for measuring your blood pressure accurately at home, as does the AHA.

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Kimberly Hayes is an editor-writer for AARP and has written on health and social justice issues for numerous organizations, including the National Organization for Women, the Robert Wood Johnson Foundation and the Lawyers’ Committee for Civil Rights. She previously served as editor of Native American Report.

Dr. Merle Myerson is a board-certified cardiologist with specialties in sports medicine, lipids, women’s health and prevention of cardiovascular disease.

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