Understanding the Basics of High Blood Pressure

Know your numbers and take steps to manage hypertension.

blood pressure reading

Updated on September 14, 2023.

High blood pressure—also known as hypertension—can be a silent killer. You may not feel it, but it could be quietly harming your blood vessels, heart, and even your kidneys and eyes.

The Centers for Disease Control and Prevention (CDC) says that nearly half of adults in the United States (roughly 120 million people) have high blood pressure. Even more alarming, many of those with high blood pressure don’t know they have it, according to the American Heart Association (AHA). And only about a quarter (22.5 percent) of people with hypertension have it under control, according to the CDC.

Read on to understand why hypertension is so dangerous and what you can do to stay healthy if you have it.

Silent killer

One reason so many people have uncontrolled hypertension is they simply don’t know their blood pressure is elevated.

“Hypertension isn’t something that’s always symptomatic,” says Gregory L. Miller, MD, a cardiologist in Grand Rapids, Michigan. “People aren’t alarmed. They’re feeling fine, so they’re not going to seek medical care.”

For people who know they have high blood pressure and still aren’t controlling it, Dr. Miller suggests they might not have adequate access to routine medical care. “A lot of people use emergency rooms or urgent care when they need it,” he says.

He also believes that some healthcare providers (HCPs) don’t treat blood pressure aggressively enough.

“A lot of times we’re faulted for not trying hard enough to reach target blood pressure numbers,” he says. “We’ll say, ‘We’ve got it under 160/90 and that’s good enough,’ or, ‘The patient is elderly, and I don’t want to push too hard.’”

What is an ideal blood pressure level?

A blood pressure reading has two elements: systolic, the top number, and diastolic, the bottom number. Healthcare providers (HCPs) measure these readings in millimeters of mercury (mm Hg). 

A normal blood pressure level is under 120/80 mm Hg. Between 120 and 129 systolic and under 80 mm Hg diastolic is considered elevated. Anything over 130 on the top or 80 on the bottom is considered hypertension.

These are pretty solid guidelines, says Miller, but he also notes that one’s blood pressure can change frequently. Blood pressure is usually highest in the morning when there are more catecholamines—chemicals like adrenaline—in the blood.

There’s also day-to-day variation based on factors like diet, hydration, and weather. There’s even a phenomenon called “white coat hypertension” where people have higher blood pressure in an HCP’s office, possibly due to stress or anxiety around seeing an HCP.

Risk factors for high blood pressure

Factors that may increase your risk for high blood pressure include:

  • Age: Blood pressure tends to rise for almost everyone as they get older. Around 90 percent of Americans will develop hypertension by the time they reach between 55 and 65 years of age. Anyone over the age of 40 should get their blood pressure checked at least once a year.
  • Race: Black American adults are at a greater risk for high blood pressure (56 percent) than Hispanic (39 percent) and non-Hispanic white Americans (48 percent). Hypertension is also thought to develop at an earlier age in Black Americans then in other groups.
  • Sex: People assigned male at birth are more likely to have hypertension (50 percent) than people assigned female at birth (44 percent). They are also more likely to develop it until the age of 64. People assigned female at birth are at higher risk from the age of 65 and up.
  • Family history: If you have an immediate family member (like a parent or sibling) with hypertension, you’re more likely to develop the condition. This can be due to a mix of genetics and the environment and lifestyle you share with your family.

Complications of hypertension

High blood pressure can damage arteries, which can lead to plaque buildup and atherosclerosis, a major risk factor for heart attacks, strokes, and heart failure. But the consequences of high blood pressure aren’t limited to the heart and the blood vessels. It can also cause kidney damage.

“High blood pressure is a big cause and one of the few treatable causes of kidney damage,” Miller says. Kidney damage from high blood pressure is called hypertensive nephropathy.

“Everything—coronary artery disease, heart failure—gets worse from renal insufficiency [poor kidney function],” says Miller.

Hypertension can damage the blood vessels in your eyes, as well. This condition is called hypertensive retinopathy. It can potentially lead to double vision, headaches, and even vision loss. High blood pressure also puts you at risk for damage to eye nerves and blockages in the blood vessels that deliver blood to the eyes.

Lifestyle changes can help

Treatment for high blood pressure usually starts with monitoring your blood pressure regularly. Your HCP can do this with a simple test in their office. You can also do it from home or, in many cases, at a local pharmacy.

To start bringing down your numbers, changes to diet and exercise are typically recommended. Your HCP can create a plan tailored for you to lower blood pressure and improve the effectiveness of other treatments.

“We’ve seen a number of people who have successfully lost weight and their blood pressure gets much better,” says Miller. “And we ask people to limit sodium because eating too much sodium increases water retention and blood pressure.”

The most common lifestyle changes HCPs recommend include:

  • Following a well-balanced, low-salt eating plan like the DASH Diet
  • Reducing the amount of alcohol you drink
  • Getting regular exercise
  • Taking steps to manage stress
  • Maintaining a healthy body weight

The AHA recommends limiting your sodium intake to 2,300 milligrams (mg) per day, roughly equivalent to 1 teaspoon of salt. To control or prevent hypertension, some people may need to consume less than this, around 1,500 mg per day or less.

Treatment may involve medication

For some people, diet and exercise might not be enough to reduce elevated blood pressure. “Most people need medication,” Miller notes.

Drug treatment for hypertension usually consists of one or more medications, such as ACE inhibitors, angiotensin II receptor blockers, calcium channel blockers, and diuretics.

The bottom line on blood pressure

High blood pressure can develop with no outward symptoms. That means it’s crucial to make regular visits to an HCP and routine blood pressure checks a part of your overall health strategy. The good news is that even if your blood pressure is high, there are plenty of medication and lifestyle-based treatments for hypertension that may help.

Article sources open article sources

Centers for Disease Control and Prevention. Facts About Hypertension. Page last reviewed July 6, 2023.
American Heart Association. The Facts About High Blood Pressure. Page last reviewed May 25, 2023.
Mayo Clinic. High blood pressure (hypertension). September 15, 2022.
Centers for Disease Control and Prevention. High Blood Pressure Symptoms and Causes. Page last reviewed May 18, 2021.
Lopez-Jimenez, Francisco. Blood pressure: Does it have a daily pattern? Mayo Clinic. Accessed on July 26, 2023.
Armstrong S, Bain JR, Crawford M, et al. Disrupted circadian rhythm in catecholamines in youth-onset type 2 diabetes. Journal of the Endocrine Society. 2022;6(1):A613-A614.
Cleveland Clinic. White Coat Syndrome. Page last reviewed August 3, 2022.
Poznyak AV, Sadykhov NK, Kartuesov AG, et al. Hypertension as a risk factor for atherosclerosis: Cardiovascular risk assessment. Front Cardiovasc Med. 2022 Aug 22;9:959285.
American Heart Association. Understanding Blood Pressure Readings. Page last reviewed May 30, 2023.
National Institute of Diabetes and Digestive and Kidney Diseases. High Blood Pressure & Kidney Disease. Page last reviewed March 2020.
Centers for Disease Control and Prevention. The Surprising Link Between Chronic Kidney Disease, Diabetes, and Heart Disease. Page last reviewed July 12, 2022.
Mayo Clinic. High blood pressure dangers: Hypertension’s effects on your body. January 14, 2022.
Kim, Judy E. Hypertensive Retinopathy. American Academy of Ophthalmology. Page last reviewed July 26, 2023.
Johns Hopkins Medicine. Hypertension: What you need to know as you age. Accessed on July 27, 2023.
Centers for Disease Control and Prevention. Know Your Risk for High Blood Pressure. Page last reviewed March 17, 2023.
American Heart Association. Changes You Can Make to Manage High Blood Pressure. Page last reviewed June 1, 2023.
American Heart Association. What You Should Know About Blood Pressure Medications. Page last reviewed June 5, 2023.
American Heart Association. Shaking the Salt Habit to Lower High Blood Pressure. Page last reviewed June 1, 2023.

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