Diastolic Blood Pressure
Diastolic blood pressure measures the pressure in your blood vessels between heartbeats (when your heart is resting). Represented by the bottom number in a blood pressure reading, diastolic blood pressure is considered low when the blood pressure reading is below 60; a diastolic blood pressure reading higher than 90 is considered high. Lifestyle changes, such as losing weight, can help lower diastolic blood pressure.
Diastolic Blood Pressure: What Is It?
Blood pressure is the amount of force (pressure) that blood exerts on the walls of the blood vessels as it passes through them. There are two pressures measured for blood pressure:
- Pressure while the heart is beating (known as systolic blood pressure)
- Pressure while it is relaxed (known as diastolic blood pressure).
Diastolic blood pressure measures the pressure in your blood vessels between heartbeats, when your heart is resting.
How Is Diastolic Blood Pressure Measured?
When measuring diastolic blood pressure, a cuff of fabric is wrapped around the arm and then slightly inflated. The blood pressure shows up on a gauge attached to the cuff. The healthcare provider reads the numbers from the gauge as air is released from the cuff. This device that reads blood pressure is called a sphygmomanometer. Blood pressure can also be measured with a blood pressure machine.
The two numbers that measure your blood pressure are written like a fraction: one number on top and one on the bottom. For example, what many people consider normal blood pressure is read as 120/80. The number on top is the systolic pressure. It measures the pressure inside your blood vessels at the moment your heart beats. The number on the bottom is your diastolic blood pressure. It measures the pressure when your heart is between beats.
Diastolic blood pressure changes frequently throughout the day. Things that can make diastolic blood pressure change within a few minutes include:
- Level of exercise
- Amount of tension
- Nicotine use.
Therefore, it's best to use several blood pressure readings to arrive at your average blood pressure.
Be sure to look at your overall health, lifestyle, diet, and family history when comparing your blood pressure to what's considered "normal blood pressure." These factors may cause you to have a higher or lower blood pressure than what's considered normal.