Systolic vs Diastolic Blood Pressure

The force which the blood exerts on the walls of the blood vessels is called blood pressure. As the heart beats, it pumps blood through a system of blood vessels, which carry blood to every part of the body. 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.

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.

Comparison chart

Improve this 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 the monitoring blood pressure in younger individuals.	As a person's age increases, so too 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.
Blood Pressure reading:	The lower number is diastolic pressure.	The higher number is the systolic pressure.
Ventricles of the heart:	Fill with blood	Left ventricles contract
Etymology:	"Diastolic" comes from the Greek diastole meaning "a drawing apart."	"Systolic" comes from the Greek systole meaning "a drawing together or a contraction."
Blood Vessels:	Relaxed	Contracted

1 Blood pressure reading
2 Measuring Systolic and Diastolic Blood Pressure
3 Normal Range for Diastolic/Systolic Pressure
4 Age Factor
5 See Also
6 References

edit 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.

edit 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.

edit Normal Range for Diastolic/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.

An adult is considered suffering from

hypotension if the diastolic reading is < 60 mmHg and systolic reading is < 90 mmHg
Prehypertension if the diastolic reading is 81 – 89 mmHg and systolic reading is 121 – 139 mmHg
Stage 1 Hypertension if the diastolic reading is 90 – 99 mmHg and systolic reading is140 – 159 mmHg
Stage 2 Hypertension if the diastolic reading is= 100 mmHg and systolic reading is = 160 mmHg

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

edit Age Factor

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

edit See Also

edit References

Comments: Diastolic vs Systolic

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Anonymous comments

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 on 2013-03-26 02:11:36