Each time the heart beats, it sends blood throughout the body at a specific pressure. A blood pressure reading measures the amount of blood pressure in the arteries at different times. If blood pressure is too low, tissues may become starved of oxygen. If blood pressure is too high, it can put excess pressure on the blood vessels and lead to permanent damage.
Considerations
Normal blood pressure consists of two numbers: systolic and diastolic. Although the American Heart Association has guidelines for what is defined as normal blood pressure, what is considered normal may vary slightly based on each individual.
Systolic
Systolic blood pressure is the top number in a blood pressure reading. Systolic blood pressure measures the amount of pressure in the arteries when the heart contracts. In order to be considered normal, systolic blood pressure should be below 120 mm Hg.
Diastolic
Diastolic blood pressure is the bottom number in a blood pressure reading. Diastolic blood pressure is used to measure the amount of pressure in the arteries between beats, when the heart relaxes. Normal diastolic pressure is defined as less than 80 mm Hg.
