Understanding Blood Pressure Readings

What do your blood pressure numbers mean?

High blood pressure, also known as hypertension, can lead to serious health problems including heart attack or stroke. Measuring your blood pressure is the only way to know if you have it. Controlling high blood pressure can help prevent major health problems.

Healthy and unhealthy blood pressure ranges 

BLOOD PRESSURE CATEGORY SYSTOLIC mm Hg (upper number) and/or DIASTOLIC mm Hg (lower number)
NORMAL LESS THAN 120 and LESS THAN 80
ELEVATED 120 – 129 and LESS THAN 80
HIGH BLOOD PRESSURE (HYPERTENSION) STAGE 1 130 – 139 or 80 – 89
HIGH BLOOD PRESSURE (HYPERTENSION) STAGE 2 140 OR HIGHER or 90 OR HIGHER
HYPERTENSIVE CRISIS (consult your doctor immediately) HIGHER THAN 180 and/or HIGHER THAN 120

Note: Only a doctor or other medical professional can confirm a high blood pressure diagnosis. They also can check if your blood pressure is too low.

View or print this chart

Controlling blood pressure

If your blood pressure is in the normal range, stick with heart-healthy habits such as following a balanced diet and getting regular exercise.

If your blood pressure is elevated, work with your health care professional to control the condition.

In hypertension Stage 1, your health care professional should prescribe lifestyle changes. They may consider adding medication based on your risk of heart disease or stroke and should add medication if you have other conditions such as diabetes, heart failure and kidney disease.

In hypertension Stage 2, your health care professional should prescribe blood pressure medication and lifestyle changes.

In hypertensive crisis, you need medical attention.

  • Wait five minutes after your first reading.
  • Take your blood pressure again.

If your readings are still unusually high, contact your health care professional immediately.

Call 911 if your blood pressure is higher than 180/120 and you are having:

  • chest pain
  • shortness of breath
  • back pain
  • numbness
  • weakness
  • change in vision
  • difficulty speaking  

Your blood pressure numbers and what they mean

Your blood pressure is recorded as two numbers:

  • Systolic blood pressure is the first number. It measures the pressure your blood is pushing against your artery walls when the heart beats.
  • Diastolic blood pressure is the second number. It measures the pressure your blood is pushing against your artery walls while the heart muscle rests between beats.

Which number is more important?

A higher systolic or diastolic reading may be used to diagnose high blood pressure. But the systolic blood pressure tells more about risk factors for heart disease for people over 50. As people get older, their systolic blood pressure usually goes up because:

  • Large arteries become stiffer
  • There is more plaque buildup over time
  • Higher rates of heart and blood vessel diseases

Read more about high blood pressure.