How Is Hypertension Diagnosed?

Maintaining good cardiovascular health is an important part of living an overall healthy lifestyle, but high blood pressure is affecting more and more people in the US. Centers for Disease Control and Prevention (CDC) estimates that nearly half of Americans have high blood pressure¹, while only one in four have it under control.

Blood pressure often goes undiagnosed as there are few side effects, explaining why it’s a regular part of any routine check-up. You can check your blood pressure at home or make regular appointments to see your doctor.

There are several effective strategies for keeping your blood pressure in check, including lifestyle changes and medications, but how do you get a diagnosis?

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What is blood pressure?

Blood pressure is the force blood exerts on the artery walls. Arteries are blood vessels that carry blood from your heart to other parts of your body, supplying your organs, tissues, and muscles. It's normal for your blood pressure to fluctuate slightly throughout the day depending on what you're doing.

A blood pressure reading is made of two numbers:

  • Systolic blood pressure (the first number) measures the pressure in your arteries when your heart pumps

  • Diastolic blood pressure (the second number) measures the pressure in your arteries when your heart is resting between pumps

A blood pressure reading of 120mm Hg systolic and 80mm Hg diastolic (written as 120/80mm Hg) is considered “normal.” You might hear your doctor say “your blood pressure is 120 over 80.”

When is blood pressure considered high?

High blood pressure (hypertension), is blood pressure that is higher than 120/80mm Hg. While it’s normal for your blood pressure to rise and fall slightly throughout the day (when you exercise, for example), you may be diagnosed with hypertension if your blood pressure consistently stays above the normal range.

High blood pressure ranges can be categorized.

Elevated blood pressure

You might have elevated blood pressure if your readings show your systolic blood pressure is 120–129mm Hg and your diastolic blood pressure is below 80mm Hg. Elevated blood pressure gradually gets worse over time without treatment.

Stage 1 hypertension

This consists of systolic blood pressure of 130–139mm Hg and diastolic blood pressure of 80–89mm Hg.

Stage 2 hypertension

A systolic blood pressure of 140mm Hg or higher and/or diastolic blood pressure of 90mm Hg or higher suggests you might have stage 2 hypertension.

Hypertensive crisis

Seek medical attention right away if your blood pressure reading is higher than 180/120mm Hg. If you see this reading when taking your blood pressure at home, wait five minutes and take your blood pressure again to ensure it’s accurate. Get urgent medical help if your blood pressure reading is still high.

Signs and symptoms of high blood pressure

Most people with hypertension have no symptoms at all, but high blood pressure that’s severe and life-threatening might cause symptoms, including:

  • Shortness of breath

  • Vision changes

  • Headaches

  • Nausea

  • Nosebleeds

  • Loss of consciousness

Get emergency medical help if you have any of these symptoms.

Who is at risk of high blood pressure?

High blood pressure in some people develops gradually over time with no known cause. For others, high blood pressure develops quickly for a specific reason, such as taking certain medications or developing another medical condition.

Different factors can increase your risk of developing high blood pressure, including:


The more you age, the more likely it is that you’ll develop high blood pressure. In men, high blood pressure is more common before the age of 64. In women, high blood pressure is more common after the age of 65 or post-menopause.


You’re more likely to develop high blood pressure if it runs in your family.


If you’re overweight or obese, your body will have to produce more blood and work harder to push blood around your body. This can cause high blood pressure² and put strain on your arteries.


Hypertension is more common in Black people³, particularly in younger individuals. As a result, black people are more likely to experience high blood pressure complications, including strokes and heart attacks.


Smoking⁴ can immediately elevate your blood pressure and increase your chance of developing heart disease and other cardiovascular problems in the long term.

Poor diet

If you regularly consume high-sodium food, your body will retain water and your blood pressure will rise. Not getting enough potassium in your diet can also affect the sodium levels in your blood, increasing your risk of high blood pressure.

Drinking too much alcohol

Consuming alcohol excessively⁵ can cause cardiovascular problems, including high blood pressure. The American Heart Association (AHA) recommends that women consume no more than one alcoholic drink a day and no more than two drinks a day for men.

Sedentary lifestyle

Not exercising regularly can cause high blood pressure and lead to obesity, a major risk factor for high blood pressure and other serious diseases.


Some women develop high blood pressure while they are pregnant. As the body changes and grows, the heart needs to work harder to supply the organs and muscles with blood.

Medical conditions

Other health conditions can cause high blood pressure, including diabetes, thyroid disease, kidney disease, and sleep apnea.


Stressful situations can cause your blood pressure levels to spike temporarily, while chronic stress causes frequent spikes over a long period that can damage your body. People who are stressed are also more likely to adopt an unhealthy lifestyle⁶, by eating unhealthy food, drinking too much alcohol, living a sedentary lifestyle, or smoking, which can increase the risk of hypertension.


Medications such as nonsteroidal anti-inflammatories (NSAIDs), decongestants, and the combined contraceptive pill can increase your blood pressure. Illicit drugs such as cocaine and amphetamines can also cause hypertension.

Can children get high blood pressure?

One in 25 young people aged between 12 and 19 have high blood pressure in the US⁷, but it is generally more common in adults.

Children can develop high blood pressure because of an underlying health condition, such as a heart or kidney condition, or because they have an unhealthy lifestyle.

What are the complications of high blood pressure?

Over time, high blood pressure can damage your arteries, heart, and other organs. The longer you live with high blood pressure, the more likely it is to damage your body.

Untreated hypertension can cause many serious health concerns, including:

  • Aneurysm

  • Heart attack

  • Stroke

  • Heart failure

  • Damage to the blood vessels in your eyes

  • Damage to the blood vessels in your kidneys

  • Metabolic syndromes 

  • Memory problems and dementia

How is high blood pressure diagnosed?

You’ll probably have your blood pressure checked every time you see your doctor for a routine check-up, even if you don’t have symptoms. It’s a good idea to have your blood pressure checked at least every two years from the age of 18. After 40, try to have your blood pressure checked at least every 12 months.

Your doctor may recommend you have your blood pressure checked more frequently if you have already been diagnosed with hypertension or you’re at risk of developing it.

You can check your blood pressure at home or in a pharmacy with a pressure-measuring arm cuff, but this is more likely to result in an inaccurate reading. It's best to visit your doctor for an accurate blood pressure reading.

During your appointment, your doctor will perform a physical exam and ask questions about your medical history, including what medications you’re currently taking. They will place an inflatable arm cuff (a sphygmomanometer⁸) around your arm. Once the cuff is filled with air, it presses against the brachial artery and temporarily stops blood flow. When the air is released, the machine will monitor your blood pressure.

If it’s been a while since you’ve had your blood pressure checked, your doctor might take a reading using both arms for more accuracy. Your doctor might ask you to come in for another blood pressure check if the reading is not within the normal range.

Hypertension is usually diagnosed after three high readings where your systolic blood pressure reading is equal to or above 130mm Hg and/or your diastolic blood pressure is equal to or above 80mm Hg.

Your doctor will assess both blood pressure numbers, but the systolic number is more important for people over the age of 50. Isolated systolic hypertension — where the diastolic blood pressure is normal, but the systolic blood pressure is above 130mm Hg — is more common in people over the age of 65.

Other tests for high blood pressure

Your doctor may recommend further testing to determine the cause of your high blood pressure readings and create an individualized treatment plan to help manage the condition. Other tests for high blood pressure include:

Lab tests

Blood tests and urine tests may be necessary to check the health of your kidneys and your levels of salt, sugar, cholesterol, and hormones.

Electrocardiogram (EKG)

This test will measure your heart's electrical activity.


An echocardiogram uses sound waves to create an image of the heart which can be useful in diagnosing cardiovascular illnesses, including high blood pressure.

Testing your blood pressure at home

Your doctor might ask you to check your blood pressure at home to give them a more complete picture of how your blood pressure changes. This is particularly useful if you suffer from white-coat syndrome as your blood pressure is measured in the comfort of your own home.

Blood pressure monitors are affordable and easy to find, and you don’t need a prescription to get one. However, you should choose a brand recommended by your doctor with a cuff that comfortably fits your arm. Wrist or finger blood pressure machines are not recommended by the American Heart Association (AHA).

You might be given an ambulatory monitoring machine to measure your blood pressure at regular intervals over 24 hours. Significant blood pressure fluctuations throughout the day and night could suggest you have high blood pressure or that your medication needs to be adjusted.

Avoid smoking, drinking caffeinated beverages, or exercising within 30 minutes of measuring your blood pressure as this could lead to an inaccurate reading.

How is high blood pressure treated?

In most cases, blood pressure can be controlled with a variety of treatment options and lifestyle changes.

Lifestyle changes

Your doctor may recommend one or more of the following lifestyle changes to help manage your blood pressure:

Medications for high blood pressure

You might need to take medication if lifestyle changes have not effectively lowered or maintained your blood pressure.

Your ideal blood pressure depends on factors like your health and age, and your doctor will consider these factors when prescribing medication. Some people find that taking a combination of medications is the best way to maintain a normal blood pressure level.

The following medications are used to treat high blood pressure:


Also known as water pills, diuretics help your kidneys flush out water and sodium which can lower blood pressure.

Your doctor may prescribe a potassium-sparing diuretic to help treat your high blood pressure, as diuretics can cause you to urinate more frequently, removing more potassium from your body. Potassium plays an important role in maintaining healthy blood pressure, so it’s important you have enough of it.

Angiotensin-converting enzyme (ACE) inhibitors

ACE inhibitors block the creation of angiotensin-converting enzymes. This enzyme causes your blood vessels to narrow, which can elevate your blood pressure.

Calcium channel blockers

This help relax the muscles in your blood vessels and slow your heart rate.

Angiotensin II receptor blockers (ARBs)

ARBs allow your blood vessels to relax by reducing the effectiveness of the angiotensin II hormone.


Beta-blockers can be combined with other hypertension medications to widen your blood vessels and reduce your blood pressure.


Alpha-blockers prevent the hormone norepinephrine from narrowing your blood vessels and decreasing blood flow, which can cause high blood pressure.

The lowdown

High blood pressure occurs when your blood exerts too much pressure on your artery walls. Men are more likely to develop hypertension before the age of 65 and women after menopause.

Hypertension rarely causes symptoms, so it is often missed. Untreated high blood pressure raises your risk of serious health problems, including heart attack and stroke. You should try to get your blood pressure checked at least once a year, at home or at the doctor’s surgery. If your healthcare provider diagnoses you with high blood pressure, a combination of lifestyle changes and medications can help manage and treat your condition.

Have you considered clinical trials for High blood pressure?

We make it easy for you to participate in a clinical trial for High blood pressure, and get access to the latest treatments not yet widely available - and be a part of finding a cure.

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