Elevated Blood Pressure

A blood pressure test is done to diagnose elevated blood pressure. A blood pressure test may be done as a part of a routine health checkup or as a screening for high blood pressure (hypertension).

Blood pressure is measured in millimeters of mercury (mm Hg). A blood pressure measurement has two numbers:

• The top number (systolic) is the pressure of the blood flow when the heart muscle squeezes (contracts), pumping blood.
• The bottom number (diastolic) is the pressure in the arteries measured between heartbeats.

Elevated blood pressure is a measurement of 120 to 129 millimeters of mercury (mm Hg) and a bottom number below (not above) 80 mm Hg.

A diagnosis of elevated blood pressure is based on the average of two or more blood pressure readings. The measurements should be taken on separate occasions in the same way. The first time your blood pressure is checked, it should be measured in both arms to determine if there’s a difference. After that, the arm with the higher reading should be used.

A longer blood pressure monitoring test can be done to check blood pressure at regular times over six or 24 hours. This is called ambulatory blood pressure monitoring. However, the devices used for the test aren’t available in all medical centers. Check with your insurer to see if ambulatory blood pressure monitoring is a covered service.

Your provider might also suggest that you check your blood pressure at home. Home blood pressure monitors are available at local stores and pharmacies. Some devices store the measurements in its memory.

Tests

If you have elevated or high blood pressure, your health care provider may do blood and urine tests to check for conditions that can cause it. Tests may include:

• Complete blood count
• Cholesterol test (lipid profile)
• Blood sugar (glucose) test
• Kidney function tests
• Thyroid function tests

Other tests may also be done.

You might also have an electrocardiogram (ECG/EKG) to check how the heart is beating. An electrocardiogram (ECG) is quick and painless. During an ECG, sensors (electrodes) are attached to the chest and sometimes to the arms or legs. Wires connect the sensors to a machine, which prints or displays results.