Mayo Clinic Health Manager
Get free personalized health guidance for you and your family.
Get Started
About our e-newsletters
- Free e-newsletters
- Mayo Clinic expertise
- We do not share your e-mail address
Housecall, our weekly general-interest e-newsletter, keeps you up to date on a wide variety of health topics with timely, reliable, practical information, recipes, blogs, questions and answers with Mayo Clinic experts and more. Our biweekly topic-specific e-newsletters also include blogs, questions and answers with Mayo Clinic experts, and other useful information that will help you manage your health.
Housecall Archives
Mayo Clinic Housecall
Stay up to date on the latest health information.
What you get
- Free weekly e-newsletter
- Mayo Clinic expertise
- Recipes, tools and other helpful information
- We do not share your e-mail address
Tests and diagnosis
By Mayo Clinic staffBlood pressure is measured with an inflatable arm cuff and a pressure-measuring gauge. A blood pressure reading, given in millimeters of mercury (mm Hg), has two numbers. The first, or upper, number measures the pressure in your arteries when your heart beats (systolic pressure). The second, or lower, number measures the pressure in your arteries between beats (diastolic pressure).
The latest blood pressure guidelines, issued in 2003 by the National Heart, Lung, and Blood Institute, divide blood pressure measurements into four general categories:
- Normal blood pressure. Your blood pressure is normal if it's below 120/80 mm Hg. However, some doctors recommend 115/75 mm Hg as a better goal. Once blood pressure rises above 115/75 mm Hg, the risk of cardiovascular disease begins to increase.
- Prehypertension. Prehypertension is a systolic pressure ranging from 120 to 139 mm Hg or a diastolic pressure ranging from 80 to 89 mm Hg. Prehypertension tends to get worse over time. Within four years of being diagnosed with prehypertension, nearly one-third of adults ages 35 to 64 and nearly half the adults age 65 or older develop high blood pressure.
- Stage 1 hypertension. Stage 1 hypertension is a systolic pressure ranging from 140 to 159 mm Hg or a diastolic pressure ranging from 90 to 99 mm Hg.
- Stage 2 hypertension. The most severe hypertension, stage 2 hypertension is a systolic pressure of 160 mm Hg or higher or a diastolic pressure of 100 mm Hg or higher.
Both numbers in a blood pressure reading are important. But after age 50, the systolic reading is even more significant. Isolated systolic hypertension (ISH) — when diastolic pressure is normal but systolic pressure is high — is the most common type of high blood pressure among people older than 50.
Your doctor will likely take two to three blood pressure readings each at two or more separate appointments before diagnosing you with high blood pressure. This is because blood pressure normally varies throughout the day — and sometimes specifically during visits to the doctor, a condition called white-coat hypertension. Your doctor may ask you to record your blood pressure at home and at work to provide additional information. Measuring your blood pressure at home can also help diagnose masked hypertension, a condition in which your blood pressure is lower than it normally is when you visit the doctor's office.
If you have any type of high blood pressure, your doctor may recommend routine tests, such as a urine test (urinalysis), blood tests and an electrocardiogram (ECG) — a test that measures your heart's electrical activity. More extensive testing isn't usually needed, at least initially.
