Blood pressure readings are normally taken by a doctor, nurse or technician during routine physical exams and more frequently when readings are abnormal. The readings, which are expressed as two numbers in millimeters of mercury (mmHg) represent the pressure exerted on the walls of your arteries as blood is pumped through your body.
Types
There are two types of blood pressure readings: systolic and diastolic. Systolic is the measure of blood pressure when the heart contracts. Diastolic is the pressure when the heart relaxes.
Function
Blood pressure readings determine your risk of developing hypertension (high blood pressure) or hypotension (low blood pressure).
Method
An inflatable cuff wrapped around your upper arm is inflated to stop blood flow in an artery. As the cuff deflates, your physician or technician records the points at which blood starts to pulse again and when it stops. The result is your blood pressure reading.
Range
An optimal blood pressure reading is 120 systolic/80 diastolic. A high-normal blood pressure reading ranges from 120/80 to 139/89; high blood pressure is 140/90 and higher. A low blood pressure reading is 90/60 and below.
Significance
High blood pressure is a risk factor for heart disease, heart attack, stroke and kidney disease. Low blood pressure is normal for some people; it is only dangerous if it is sudden and causes dizziness, fainting or shock.
Considerations
Blood pressure readings vary throughout the day for a variety of reasons and under different conditions. Several readings must be taken to get an accurate average measure.
