When the heart is at rest, between beats, your blood pressure falls. This is the diastolic pressure. Blood pressure is always given as two numbers, the systolic and diastolic pressures. Both are important. The systolic pressure is the first or top number, and the diastolic pressure is the second or bottom number (for example, 120/80). If your blood pressure is 120/80, you say that it is “120 over 80”.
Both of these numbers do not need to be high for you to have high blood pressure. Either one or both can be high for you to have high blood pressure.
The diastolic blood pressure has been and remains, especially for younger people, an important hypertension number.
Research has shown that higher diastolic blood pressure is a significant risk factor for heart attacks, strokes, kidney failure, and other serious conditions.
As people become older, especially after the age of 55, the diastolic pressure will begin to decrease, while the systolic blood pressure usually begins to rise and becomes more important.