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High blood pressure (hypertension)

Medically reviewed by Last updated on Feb 1, 2023.

What is High blood pressure (hypertension)?

Harvard Health Publishing

Blood pressure has two components:

Blood pressure is measured in millimeters of mercury (mm Hg). So blood pressure would be expressed, for example, as 120/80 mm Hg.

High blood pressure is diagnosed when one or both of these numbers is too high. High blood pressure is also called hypertension.

For decades, high blood pressure was defined as 140/90 mm Hg. In November, 2017, new United States guidelines lowered the threshold for diagnosing the condition. According to new guidelines, anyone with a reading of 130/80 mm Hg or higher has blood pressure. Based on this new definition, nearly half of Americans now fall into this group.

Blood pressure is now categorized as follows:

Although high blood pressure can cause symptoms such as headache and pounding heartbeat, it often causes no symptoms at all.

So why worry about high blood pressure? Because even when high blood pressure is not causing any symptoms, it can silently damage many organs, including the

You may not recognize the damage that silent hypertension has been doing to your body until you suddenly are stricken with a major disease. For example, hypertension increases your risk of heart attack, stroke, and kidney failure.

High blood pressure (hypertension)


Usually, hypertension does not directly cause symptoms. When blood pressure is very high, it can cause headaches, dizziness, fatigue or visual symptoms.


The diagnosis of hypertension depends on blood pressure readings. Therefore, it's essential that blood pressure be measured carefully.

To obtain an accurate blood pressure measurement:

If your blood pressure is high, your doctor should examine your eyes, heart, and nervous system, to look for evidence of damage from hypertension.

If there is no such evidence, your doctor will likely want to recheck your blood pressure again in a few weeks or have you monitor your blood pressure at home. If your blood pressure is extremely high, your doctor may want to start medication immediately.

If you are diagnosed with hypertension, other tests will check for organ damage. These tests can include:


To prevent high blood pressure:

Hypertension increases your risk of heart attack and stroke. So it is important to modify your risk factors for coronary artery disease. In addition to the above actions, you should

You may be able to cure your hypertension with lifestyle changes alone. Simply changing what you eat and drink can bring down systolic blood pressure by as much as 11 points, according to some estimates.


Elevated blood pressure. If your blood pressure is simply elevated, meaning the first number (systolic blood pressure) falls in the range of 120 to 129 while the second number (diastolic blood pressure) remains below 80, medication is not recommended. Instead, you should focus on healthy lifestyle changes:

Stage 1 hypertension. You have stage 1 hypertension if your systolic blood pressure is 130 to 139, your diastolic pressure is 80 to 89, or both. Even if your systolic blood pressure hovers above 130, you still may not need medication immediately. Your doctor may suggest a trial of lifestyle changes first if you don't have heart disease and you have a low risk of developing it over the next 10 years. But many people find that they need to take some type of medication in order to reduce their blood pressure numbers to healthier levels.

Stage 2 hypertension. You have stage 2 hypertension if your systolic pressure is at least 140 mm Hg, your diastolic pressure is at least 90 mm Hg, or both. In addition to lifestyle modifications, you will likely need to start medication to lower your blood pressure. That doesn't mean you will always need drug therapy. Losing weight, decreasing stress, eating healthier, and exercising daily can potentially bring your readings into the normal range. But even if you still need medication, your lifestyle efforts help prevent you from needing higher drug doses in the future.

Examples of commonly used antihypertensive medications include:

People with diabetes, kidney disease or heart problems are at higher risk of complications from hypertension. As a result, they are usually treated more aggressively with medications.

Treatment options

The following list of medications are related to or used in the treatment of this condition.

View more treatment options

When to call a professional

Adults should have their blood pressure measured at least every few years.

If your blood pressure is 120/80 mm Hg or higher, schedule regular appointments with your doctor. Have your blood pressure monitored more regularly. And get advice about modifying your lifestyle to prevent future problems.


The prognosis for hypertension depends on

Hypertension can lead to a poor prognosis even if you do not have symptoms.

When high blood pressure is treated adequately, the prognosis is much better. Both lifestyle changes and medicines can control your blood pressure.

Additional info

American Heart Association

National Heart, Lung, and Blood Institute (NHLBI)

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.