What is blood pressure? Blood pressure is the force of blood in the arteries. When the heart beats, blood propels in the arteries with force. This is called systolic blood pressure. When the heart relaxes after each beat, the force of the blood flow drops. This is called diastolic blood pressure. Blood pressure is measured in millimeters of mercury (mmHg). Blood pressure readings are expressed as two numbers, such as 140/90 mm Hg. The top number, 140, refers to systolic blood pressure and 90 refers to diastolic blood pressure. Both of these numbers are important. The blood pressure may be high or low. We discuss both the situations below. High Blood Pressure (also known as Hypertension) Hypertension means high blood pressure. It is the chronic state of elevated pressure in the arteries. A person with systolic and/or diastolic blood pressures consistently above the normal range (120/80 mm Hg) is said to have hypertension. One need not have both systolic and diastolic readings high to be labeled as hypertensive. A person can have only the systolic reading high, or only the diastolic reading high. In both cases, it is still referred to as hypertension. Why it is necessary to monitor & know one’s blood pressure? High blood pressure is a major risk factor for heart attack, heart failure, stroke, impaired vision, and kidney disease. Generally, the higher the blood pressure, the greater the risk. Untreated hypertension affects all organs of the body and can shorten one's life expectancy by 10 to 20 years. The National Heart, Lung, and Blood Institutes classifies blood pressure as normal, prehypertension, hypertension stage 1, and hypertension stage 2. Hypertension and the Elderly More than half of all persons age 65 have hypertension. In many, only the systolic blood pressure will be elevated. This is often referred to as “Isolated Systolic Hypertension”. Treating high systolic blood pressure in older patients significantly decreases the risks for stroke, heart attack, and cardiovascular death. Treatment for Hypertension Your doctor may prescribe anti-hypertension medication if your blood pressure is high. There are several kinds of medication commonly taken alone or in combination. Some medications help to lower blood pressure by eliminating excess fluid and salt that accumulate in the body. The excess fluid is eliminated in the urine. Other medications keep the heart from pumping too hard and control the heart rate and blood pumped out from the heart. Low Blood Pressure Low blood pressure, or hypotension, can be a concern if it causes symptoms such as dizziness, fainting, or even shock. Dizziness or fainting could lead to a serious fall. Shock, if not treated immediately, could end in death. However, it's true that low blood pressure is actually normal for some people.