Blood pressure rises and falls during the day. When blood pressure stays elevated over time, it is called high blood pressure, or hypertension. Blood pressure is typically recorded as two numbers — the systolic pressure (as the heart beats) over the diastolic pressure (as the heart relaxes between beats). A consistent blood pressure reading of 140/90 mm Hg or higher is considered high blood pressure.
Systolic blood pressure
Systolic pressure is the force of blood in the arteries as the heart beats. It is shown as the top number in a blood pressure reading. High blood pressure is 140 and higher for systolic pressure. Diastolic pressure does not need to be high for you to have high blood pressure. When that happens, the condition is called “isolated systolic hypertension,” or ISH.
Diastolic blood pressure
Diastolic pressure is the force of blood in the arteries as the heart relaxes between beats. It’s shown as the bottom number in a blood pressure reading. The diastolic blood pressure has been and remains, especially for younger people, an important hypertension number. The higher the diastolic blood pressure the greater the risk for heart attacks, strokes and kidney failure. As people become older, the diastolic pressure will begin to decrease and the systolic blood pressure begins to rise and becomes more important. A rise in systolic blood pressure will also increase the chance for heart attacks, strokes, and kidney failure. Your physician will use both the systolic and the diastolic blood pressure to determine your blood pressure category and appropriate prevention and treatment activities.
High blood pressure is dangerous because it makes the heart work too hard. It also hardens arterial walls. High blood pressure increases the risk for heart disease and stroke, the first- and third-leading causes of death for Americans. High blood pressure can also cause other problems, such as heart failure, kidney disease, and blindness.
Causes of High Blood Pressure
The causes of high blood pressure vary. Causes may include narrowing of the arteries, a greater than normal volume of blood, or the heart beating faster or more forcefully than it should. Any of these conditions will cause increased pressure against the artery walls. High blood pressure might also be caused by another medical problem. Most of the time, the cause is not known. Although high blood pressure usually cannot be cured, in most cases it can be prevented and controlled.
How Is Blood Pressure Tested?
Having your blood pressure tested is quick and easy. Blood pressure is measured in millimeters of mercury (mm Hg) and recorded as two numbers systolic pressure “over” diastolic pressure. For example, the doctor or nurse might say “130 over 80” as a blood pressure reading. Both numbers in a blood pressure reading are important. As we grow older, systolic blood pressure is especially important.
To test your blood pressure, your doctor will use a familiar device with a long name. It is called a sphygmomanometer (pronounced sfig’-mo-ma-nom-e-ter), and may look something like this.
Effect of high blood Pressure on your Body.
Brain: High blood pressure is the most important risk factor for stroke. Very high pressure can cause a break in a weakened blood vessel, which then bleeds in the brain. This can cause a stroke. If a blood clot blocks one of the narrowed arteries, it can also cause a stroke.
Eyes: High blood pressure can eventually cause blood vessels in the eye to burst or bleed. Vision may become blurred or otherwise impaired and can result in blindness.
Arteries: As people get older, arteries throughout the body “harden,” especially those in the heart, brain, and kidneys. High blood pressure is associated with these “stiffer” arteries. This, in turn, causes the heart and kidneys to work harder.
Kidneys: The kidneys act as filters to rid the body of wastes. Over time, high blood pressure can narrow and thicken the blood vessels of the kidneys. The kidneys filter less fluid, and waste builds up in the blood. The kidneys may fail altogether. When this happens, medical treatment (dialysis) or a kidney transplant may be needed.
Heart Attack: High blood pressure is a major risk factor for heart attack. The arteries bring oxygen-carrying blood to the heart muscle. If the heart cannot get enough oxygen, chest pain, also known as “angina,” can occur. If the flow of blood is blocked, a heart attacks results.
Congestive Heart Failure: High blood pressure is the number one risk factor for congestive heart failure (CHF). CHF is a serious condition in which the heart is unable to pump enough blood to supply the body’s needs.