High blood pressure (also called hypertension) is one of six primary risk factors for heart disease. The others include obesity, diabetes, high cholesterol, a sedentary life style and cigarette smoking. High blood pressure is called a silent killer because it can contribute to a number of secondary complications like kidney failure and coronary artery disease that result in death, years before it is first detected. Many people are not aware that they have high blood pressure until it's measured in their doctor's office during an evaluation for some other problem.
A Primer on Blood Pressure
Blood pressure is the amount of pressure exerted against the inside of the arterial walls when the heart contracts. Each time the heart contracts, it pushes blood out of the left ventricle to the rest of the body, causing systolic blood pressure. When the left ventricle relaxes, it fills with blood oxygenated by the lungs and the stored energy in the arterial walls relax, causing diastolic blood pressure.
How Blood Pressure is Recorded
When your blood pressure is measured, your health care provider will record it as two numbers: the systolic blood pressure, followed by the diastolic blood pressure. The two numbers are separated with a slash and are stated as the systolic blood pressure over the diastolic blood pressure. For instance, a normal blood pressure reading is written as 120/80, or 120 over 80.
High Blood Pressure Readings
According to the National Heart Lung and Blood Institute, the normal blood pressure for adults is 120/80, or a systolic blood pressure of 120 and a diastolic blood pressure of 80. Prehypertension occurs with a systolic blood pressure between 120 and 139, and a diastolic blood pressure between 80 and 89. Stage I hypertension is defined by a systolic blood pressure between 140 and 150, and a diastolic blood pressure between 90 and 99. Stage II hypertension is defined as a systolic blood pressure of 160 or higher and a diastolic blood pressure of 100 or higher.
Implications of High Systolic Blood Pressure
Both systolic and diastolic blood pressures rise and fall throughout the day as normal responses to posture, diet, temperature and activity. However, sustained high blood pressure may indicate underlying issues that could lead to serious diseases and complications. One common form of high systolic blood pressure is called "white coat hypertension," and is caused by being in a clinical environment like your doctor's office, giving blood or some other health care facility. White coat hypertension is transient and should return to normal as soon as you leave. Other transient forms of high systolic blood pressure include reactions to fear, stress or anger. If your systolic blood pressure remains high, then it may indicate some other underlying disease and should be evaluated by your physician.
Treatable Systolic Blood Pressure
If you experience sustained high systolic blood pressure, it could represent an underlying condition that requires medical treatment. For instance, certain cardiovascular disorders like coronary artery disease can manifest itself with high systolic blood pressure. In coronary artery disease, the arteries become less distensible and occluded with calcified plaque that makes the heart work harder to push blood through the arteries, elevating the systolic blood pressure. Other factors like urological, neurological and preeclampsia conditions in women often manifest themselves with high systolic blood pressures.
