Systolic vs. Diastolic Blood Pressure

Diastolic pressure is the minimum pressure in the arteries, which occurs near the beginning of the cardiac cycle when the ventricles are filled with blood. Systolic pressure is peak pressure in the arteries, which occurs near the end of the cardiac cycle when the ventricles are contracting.

As the heart beats, it pumps blood through a system of blood vessels, which carry blood to every part of the body. Blood pressure is the force that blood exerts on the walls of blood vessels. All or any of the events related to the flow or blood pressure that occurs from the beginning of one heartbeat to the beginning of the next is called a cardiac cycle. Problems in the cardiac cycle can cause low or high blood pressure.

Comparison chart

Diastolic

Systolic

Definition It is the pressure that is exerted on the walls of the various arteries around the body in between heart beats when the heart is relaxed. It measures the amount of pressure that blood exerts on arteries and vessels while the heart is beating.
Normal range 60 – 80 mmHg (adults); 65 mmHg (infants); 65 mmHg (6 to 9 years) 90 – 120 mmHg (adults); 95 mmHg (infants); 100 mmHg (6 to 9 years)
Importance with age Diastolic readings are particularly important in monitoring blood pressure in younger individuals. As a person's age increases, so does the importance of their systolic blood pressure measurement.
Blood Pressure Diastolic represents the minimum pressure in the arteries. Systolic represents the maximum pressure exerted on the arteries.
Ventricles of the heart Fill with blood Left ventricles contract
Blood Vessels Relaxed Contracted
Blood Pressure reading The lower number is diastolic pressure. The higher number is systolic pressure.
Etymology "Diastolic" comes from the Greek diastole meaning "a drawing apart." "Systolic" comes from the Greek systole meaning "a drawing together or a contraction."

Contents: Systolic vs Diastolic Blood Pressure

Measuring blood pressure

Blood pressure reading

Blood pressure readings are measured in millimeters of mercury (mmHg) and are provided as a pair of numbers. For example, 110 over 70 (written as 110/70) systolic/diastolic.

The lower number is the diastolic blood pressure reading. It represents the minimum pressure in the arteries when the heart is at rest. The higher number is the systolic blood pressure reading. It represents the maximum pressure exerted when the heart contracts.

Measuring Systolic and Diastolic Blood Pressure

The instrument used to measure blood pressure is called a Sphygmomanometer. The blood pressure cuff is snugly wrapped around the upper arm, positioning it so that the lower edge of the cuff is 1 inch above the bend of the elbow. The head of the stethoscope is placed over a large artery then air is pumped into the cuff until circulation is cut off, then air is let out slowly.

At some point, as more and more air is let out of the cuff, the pressure exerted by the cuff is so little that the sound of the blood pulsing against the artery walls subsides and there is silence again. This is the point of lowest pressure (called Diastolic), which normally raises the mercury to about 80 millimeters.

Air is pumped into the cuff until circulation is cut off; when a stethoscope is placed over the cuff, there is silence. Then as the air is slowly let out of the cuff, blood begins to flow again and can be heard through the stethoscope. This is the point of greatest pressure (called Systolic), and is usually expressed as how high it forces a column of mercury to rise in a tube. At its highest normal pressure, the heart would send a column of mercury to a height of about 120 millimeters.

Normal Ranges for Diastolic and Systolic Pressure

In children, the diastolic measurement is about 65 mmHg. In adults it ranges from 60 – 80 mmHg. Systolic measurement in children ranges from 95 to 100 and in adults it ranges from 90 – 120 mmHg.

The normal range, as well as ranges for pre-hypertension, stage 1 hypertension and stage 2 hypertension as measured by diastolic and systolic blood pressure.
The normal range, as well as ranges for pre-hypertension, stage 1 hypertension and stage 2 hypertension as measured by diastolic and systolic blood pressure.

An adult is considered suffering from

In the past, more attention was paid to diastolic pressure but it is now recognized that both high systolic pressure and high pulse pressure (the numerical difference between systolic and diastolic pressures) are risk factors. In some cases, it appears that a decrease in excessive diastolic pressure can actually increase risk, probably due to the increased difference between systolic and diastolic pressures.

Systolic blood pressure as a single blood pressure component is usually superior to diastolic blood pressure in predicting cardiovascular risk in middle-aged and older individuals. A very high or very low diastolic blood pressure can add to the risks identified by systolic blood pressure alone.[1]

Age Factor

Diastolic readings are particularly important in monitoring the blood pressure in younger individuals. Systolic blood pressure is known to rise with age as a result of hardening of the arteries.

References

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Comments: Diastolic vs Systolic

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Anonymous comments (4)

May 9, 2014, 1:25am

my bp is at the moment 210/119 Is that too high as I dont feel well

— 49.✗.✗.57
0

November 19, 2013, 3:33am

Thanks for excellent information on Blood Pressure. For a common man, such information is always a confusion. He tries to compare the values with his own and diagnose himself, and gets into further increased problems.

The idea of publishing information on Blood Pressure is to just know about various terms related with it. These values and correlations are all theoretical for all individuals because these values does not belong to them. So, please be educated that there several hundred factors that effect blood pressure readings. If you have any variations in your readings, you need to get it diagnosed clinically by a competent physician. If you fall in stage I or stage II according to some web publications, that has nothing to do with you, as you are a different individual.
Gulbahar S Jalarch

— 122.✗.✗.245
-2

July 5, 2013, 10:27pm

I check my BP today, I am 43 years old with a systole of 126 and diastole of 80.... that classify it as pre-hypertension but, first always I have measured lower 120/80... precisely around 1 and half month ago, started to feel symptoms of agina...pain on my chest that extend to my throat. Difficult to breath, I feel tired so easy... This is suspicious and kind hypochondriac behavior I know but, everybody know their own body....

— 99.✗.✗.168
-3

March 26, 2013, 2:11am

My readings are as follows over the past year:
8/24/2012 8/28/2012 2/13/2013 3/22/2013
Systolic 142 132 124 167
Diastolic 88 80 70 102

I'm 46, 5ft 9in tall and weigh 230lbs. My recent reading is after taking cold medication and my Dr. informed that I needed to keep an eye on on BP within the next 3-4 weeks. I felt a little stressed from work and even more when they take my exams because I know I'm susceptible to high BP.
Is this really really bad (Sounds like a stupid question but I'm really looking for opinion).

— 208.✗.✗.231
-11

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