High Blood Pressure Glossary

High blood pressure, or hypertension, is a complicated disease. Studies have shown that people who understand the condition are more likely to stick with their treatment plan. Knowing the definitions of terms your doctor may use when talking with you about your blood pressure is important.

The following words refer to high blood pressure and medications often prescribed for the condition.

ACE inhibitor. A medication that inhibits ACE (angiotensin converting enzyme), which is important to the formation of angiotensin II. Angiotensin II makes arteries in the body constrict and thereby raises blood pressure. ACE inhibitors lower blood pressure by inhibiting the formation of angiotensin II. This relaxes arteries and lowers blood pressure.

Angiotensin receptor blockers (ARBs). This group of medications works by blocking the effect of angiotensin II on blood vessels. This causes the vessels to dilate, causing blood pressure to go down. Angiotensin II is a substance produced by the body that causes vessels to constrict, which increases blood pressure.

Antihypertensive. A medication that lowers high blood pressure.

Beta blockers. A type of medication that works by reducing nerve impulses to the heart and blood vessels. The heart then beats slower and with less force, causing blood pressure to drop and decreasing the heart's work load.

Blood pressure. The pressure of the blood within the arteries. It’s produced primarily by the contraction of the heart muscle. Two numbers record its measurement. The first (systolic) is measured after the heart contracts and is the highest number. The second (diastolic) is measured before the heart contracts and is the lowest number.

Calcium channel blocker (CCB). A drug that blocks the entry of calcium into the muscle cells of the heart and the arteries. The entry of calcium into these cells makes the heart contract and arteries narrow. By blocking the entry of calcium, a CCB decreases the contraction of the heart and dilates or widens the arteries. By dilating the arteries, a CCB reduces the pressure in the arteries.

DASH diet. DASH, or Dietary Approaches to Stop Hypertension, has been shown to decrease blood pressure, helping prevent and control high blood pressure. The DASH diet is rich in fruits, vegetables, and low-fat dairy foods, and low in sodium, and saturated and total fat. It also is low in cholesterol and high in fiber, potassium, calcium, and magnesium.

Diastolic. The bottom number of the blood pressure measurement. It's the amount of force blood exerts against the walls of the arteries when the heart is in a period of relaxation and dilatation or expansion, and is measured in millimeters of mercury (mm/Hg).

Diuretic. A drug that helps the kidneys to eliminate excess water. (Sometimes, people call this a "water pill.") Diuretics are often the first drugs prescribed to help control high blood pressure. They are usually given in combination with an ACE inhibitor or another potent antihypertensive.

High blood pressure/hypertension. For most healthy adults who do not have diabetes or other chronic health problem, this condition is defined as blood pressure of or exceeding 140/90 mmHg. That's a systolic pressure of 140 or higher and/or a diastolic pressure of 90 or higher on three or more separate occasions.

Prehypertension. Having this condition puts you at higher risk for developing hypertension. Prehypertension is a systolic pressure of 120 to 139 and/or a diastolic pressure of 80 to 89.

Sodium. An element that, when combined with chlorine, produces table salt. Sodium is present in other baking and cooking products, including baking powder, baking soda, and monosodium glutamate. People with high blood pressure are advised to reduce their sodium intake.

Sphygmomanometer. An instrument for measuring blood pressure that consists of a gauge attached to a rubber cuff that’s wrapped around the upper arm and inflated to compress the arteries.

Systolic. The top number of the blood pressure measurement. It's the amount of force blood exerts against the walls of the arteries when the heart is contracting, measured in millimeters of mercury (mm/Hg).

Vasodilators. A group of medications which work to make the muscles in blood vessels relax and open wider. The dilation of the blood vessels decreases blood pressure.

If you have further questions regarding these terms, ask your doctor.