High blood pressure, or hypertension, is defined in an adult as a systolic pressure of 140 mm Hg or higher and/or a diastolic pressure of 90 mm Hg or higher. Blood pressure is measured in millimeters of mercury (mm Hg).

High blood pressure directly increases the risk of coronary heart disease (which leads to heart attack) and stroke, especially along with other risk factors.

High blood pressure can occur in children or adults. It's particularly prevalent in African Americans, middle-aged and elderly people, obese people and heavy drinkers. People with diabetes mellitus, gout or kidney disease have hypertension more often.

High blood pressure usually has no symptoms. It's truly a "silent killer." But a simple, quick, painless test can detect it.

Related AHA Scientific Statements:
Hypertension

Related AHA publications:

• Heart and Stroke Facts
• Understanding and Controlling Your High Blood Pressure (also in Spanish)
• Shaking Your Salt Habit 
• Know the Facts, Get the Stats
• Managing Your Weight (also in Spanish)
• High Blood Pressure in African Americans 
• Six Steps to a Healthier Heart 
• High Blood Pressure and Stroke 
• "What Is High Blood Pressure?" and "How Can I Reduce High Blood Pressure?" in Answers By Heart kit (also in Spanish kit)
• "What Is High Blood Pressure Medicine?", "Why Should I Limit Sodium?" and "How Can I Monitor My Weight and Blood Pressure?" in Answers By Heart kit