Blood pressure readings indicate the pressure of blood against the walls of your arteries. It is shown as two numbers, which reveal the force of blood when your heart pumps and the force when your heart is at rest.
Healthy Range
According to the National Heart, Blood and Lung Institute, the normal, or ideal, range for blood pressure is 120/80 millimeters of mercury or less.
Significance
The top number--120--is called systolic pressure, which is the pressure of blood when your heart beats, forcing blood through the arteries. The bottom number--80--is called diastolic pressure, which is the pressure of your blood against arterial walls between beats.
Blood Pressure Effects
The website EMedTV explains that blood pressure varies during the day depending on emotional state, food or drugs ingested, and activities. Additionally, genetics play a role in blood pressure. Some people have a predisposition to normal or high blood pressure.
