What is high blood pressure?

High blood pressure measures the force pushing against artery walls and is divided into four categories.

What is high blood pressure?

Blood pressure measures the force pushing against your artery walls when your heart beats and when it rests. The systolic pressure (top number) measures the pressure against your artery walls when your heart beats (contracts) and pushes blood throughout circulation. The diastolic pressure (bottom number) is the pressure against your artery walls when your heart relaxes (in between beats). High blood pressure is diagnosed when the pressure against artery walls is higher than normal. Another term for high blood pressure is hypertension.

4 Blood Pressure Categories

The Joint National Committee defines four blood pressure categories.

Very High Range - Stage 2 Hypertension
Systolic (top) blood pressure 160 mm Hg or high
Diastolic (bottom) blood pressure 100 mm Hg or higher
If in this range you have hypertension (high blood pressure).

High Range - Stage 1 Hypertension
Systolic (top) blood pressure 140 - 159 mm Hg
Diastolic (bottom) blood pressure 90 - 99 mm Hg
If in this range you have hypertension (high blood pressure).

Caution Range - Prehypertension
Systolic (top) blood pressure 120 - 139 mm Hg
Diastolic (bottom) blood pressure 80 - 89 mm Hg
Take action!

Normal Range - Normal
Systolic (top) blood pressure below 120 mm Hg
Diastolic (bottom) blood pressure below 80 mm Hg
Perfect!

Usually high blood pressure is diagnosed after more than one elevated blood pressure reading.

Why is high blood pressure dangerous?

Arteries are made of muscle and tissues that allow them to be elastic and stretch. As blood pressure rises arteries are required to expand further to accommodate blood flow. High blood pressure leads to many health complications, including damage to blood vessels, the heart, and kidneys. If not treated, high blood pressure may contribute to a heart attack and death.