According to 2005 statistics from the American Heart Association, more than 73 million adults over the age of 20 have high blood pressure. Of those, 22 percent were unaware that their blood pressure was abnormally high. High blood pressure (hypertension) is called a silent killer because people can be affected by it for years before being diagnosed. Generally, there are no symptoms or side effects that would lead someone suspect that they have high blood pressure until they are diagnosed during a physical examination.
A Primer on Blood Pressure
In simple terms, blood pressure is the amount of force the blood exerts against the walls of the arteries as it travels throughout your body. Each time your heart beats, the left ventricle squeezes blood out of the heart, through a major artery called the aorta. From there, the blood travels through a wide network of arteries until it reaches its target organs and tissues. After delivering oxygen and nutrients to the tissues, the blood returns to the heart through another network of blood vessels called veins. After the blood is re-oxygenated by the lungs, the process starts again.
Systolic Blood Pressure
Blood pressure readings are divided into two numbers, separated by a slash (/). The first number is called the systolic blood pressure and represents the pressure of the blood exerted against the inside of the arterial walls each time the left ventricle of the heart contracts. The normal value for systolic blood pressure in adults is 120 mmHg (millimeters of mercury). Stress, exercise and certain disease conditions can raise the systolic blood pressure.
Diastolic Blood Pressure
Diastolic blood pressure is the amount of pressure exerted against the blood from stored energy in the arterial walls. It also represents the amount of pressure in the arteries in between heart beats, when the left ventricle is relaxing and filling with blood. The diastolic blood pressure is noted following the slash, after the systolic blood pressure. The normal value for diastolic blood pressure is 80 mmHg. Together, with the systolic blood pressure, they would be written as 120/80, or "120 over 80." Exercise and heart disease can cause abnormally high diastolic blood pressures.
High Blood Pressure
Blood pressures can vary throughout the day based on activity, posture, hydration, emotions and medications. Despite this, the body prefers to maintain a fairly even blood pressure. As we age, a number of conditions like arteriosclerosis, obesity, kidney disease and even high sodium in the diet can cause increases blood pressure. According to the National Heart, Lung and Blood Institute, more than two-thirds of adults over the age of 65 have high blood pressure. Ninety percent of people over the age of 55 are likely to get hypertension sometime in their life.
Stages of Hypertension
Normal resting blood pressure is 120/80 mmHg. Rarely does blood pressure skyrocket from normal to extremely high levels. Instead, it slowly creeps up through the years. Those diagnosed with blood pressure of 120-139/80-90 are considered to be pre-hypertensive. Pre-hypertension typically responds well to diet and exercise. Those with blood pressures of 140-159/90-99 are considered to have Stage one hypertension and can be treated effectively with medications. Those with blood pressures of 160 or higher/100 or higher are Stage Two hypertensives and should seek immediate medical care.
