Diastole vs. Systole: Know Your Blood Pressure Numbers

Diastole is the period of time when the heart relaxes between beats. Systole is the period of time when the heart contracts and pumps blood out to the body.

Blood pressure is measured in millimeters of mercury (mmHg) and is written as two numbers: the systolic pressure (top number) and the diastolic pressure (bottom number).

  • Systolic blood pressure is the pressure in the arteries when the heart contracts.
  • Diastolic blood pressure is the pressure in the arteries when the heart relaxes.

A normal blood pressure reading is less than 120/80 mmHg. If your systolic blood pressure is 120 to 129 mmHg and your diastolic blood pressure is less than 80 mmHg, you have prehypertension. If your systolic blood pressure is 130 mmHg or higher or your diastolic blood pressure is 80 mmHg or higher, you have high blood pressure.

Why is it important to know your diastolic blood pressure?

Diastolic blood pressure is important because it is a measure of how much resistance the arteries are putting up against the blood flow. When the diastolic blood pressure is high, it means that the arteries are too narrow or stiff. This can damage the arteries and lead to heart disease, stroke, and other health problems.

How can I lower my diastolic blood pressure?

There are a number of things you can do to lower your diastolic blood pressure, including:

  • Eat a healthy diet
  • Exercise regularly
  • Lose weight if you are overweight or obese
  • Quit smoking
  • Limit alcohol intake
  • Manage stress
  • Take your blood pressure medications as prescribed

If you have high blood pressure, it is important to work with your healthcare team to develop a management plan that is right for you. This plan may include lifestyle changes and medication.

Here are some additional tips for lowering your diastolic blood pressure:

  • Reduce your intake of salt. Salt can cause your blood pressure to rise by retaining fluids in your body. Aim to consume no more than 2,300 milligrams of sodium per day.
  • Eat plenty of fruits, vegetables, and whole grains. These foods are low in sodium and high in potassium, which can help to lower blood pressure.
  • Get regular exercise. Exercise helps to strengthen your heart and improve circulation. Aim for at least 30 minutes of moderate-intensity exercise most days of the week.
  • Quit smoking and limit alcohol intake. Smoking and excessive alcohol consumption can damage your arteries and lead to high blood pressure.

If you have any concerns about your blood pressure, talk to your doctor. They can help you to understand your blood pressure readings and develop a plan to lower your blood pressure if needed.