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What Your Blood Pressure Numbers Mean

Learn what the top and bottom blood pressure numbers mean, the American Heart Association categories, and when to call 911.

Two numbers, two jobs

A blood pressure reading has two numbers, such as 118 over 76. They are measured in millimeters of mercury, written "mm Hg."

  • The top number (systolic) is the pressure of your blood pushing against your artery walls when your heart beats.
  • The bottom number (diastolic) is the pressure against your artery walls while your heart rests between beats.

Both numbers matter. For people over 50, the American Heart Association says the top number tells more about the risk of heart disease.

The blood pressure categories

The American Heart Association (AHA) sorts adult readings into these groups. The 2025 high blood pressure guideline from the AHA and the American College of Cardiology uses the same groups.

  • Normal: top number under 120 and bottom number under 80.
  • Elevated: top number 120 to 129 and bottom number under 80.
  • High blood pressure, Stage 1: top number 130 to 139, or bottom number 80 to 89.
  • High blood pressure, Stage 2: top number 140 or higher, or bottom number 90 or higher.
  • Severe high blood pressure: top number higher than 180, or bottom number higher than 120, or both. The AHA also calls this level a hypertensive crisis.

Look at the word "or" in Stage 1 and Stage 2. Only one of your two numbers needs to be in that range.

One reading is not a diagnosis

One high number on its own does not mean you have high blood pressure. The AHA says only a doctor or other medical professional can confirm a diagnosis.

Your clinician also sets your personal target. The 2025 guideline names a general goal of below 130/80 for most adults. But the right number for you depends on your own health, so ask your doctor or nurse practitioner what your goal is.

The AHA explains what usually happens next:

  • At Elevated, the aim is to keep blood pressure from reaching Stage 1.
  • At Stage 1, your clinician should recommend lifestyle changes and may consider medicine, depending on your risk of heart disease or stroke.
  • At Stage 2, your clinician should prescribe medicine along with lifestyle changes.

If a reading is higher than 180/120

Stay calm. Wait at least one minute, then take your blood pressure again.

If it is still that high and you have no symptoms, contact your health care professional as soon as possible. This usually does not mean a hospital stay, but it does need prompt attention.

When to call 911

Call 911 if your blood pressure is higher than 180/120 and you have symptoms such as:

  • Chest pain
  • Shortness of breath
  • Back pain
  • Numbness or weakness
  • A change in your vision
  • Trouble speaking

Do not wait to see if your blood pressure comes down on its own. Call 911.

Willow Harbor at Home

Willow Harbor at Home provides adults on Medicare with high blood pressure a monitor that sends readings by itself, and a care team led by a nurse practitioner reviews them. When a reading is high, the team follows up during business hours. It is not an emergency service, so in an emergency, call 911.

This guide is general information, not medical advice. Talk with your doctor about your own care.

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