Systolic Blood Pressure vs. Diastolic Blood Pressure

The key difference between systolic and diastolic blood pressure is that systolic is the blood pressure in the blood vessels when heart contracts and pumps the blood in the vessels while diastolic is the blood pressure in the vessels when the heart relaxes and blood is filled in the heart chambers.

Systolic Blood Pressure vs. Diastolic Blood Pressure
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Blood pressures are of two types, i.e., systolic and diastolic blood pressure. Our heart acts like a pump which continuously pumps the blood in the body. When the heart pumps blood by contracting its muscles, it is called systole, and when the heart is relaxed, it is called diastole. Normal heart rate is 6o to 100 beats per minutes, and one cycle of contraction and relaxation completes in 0.8 seconds. Due to the pumping of blood in the vessels, the pressure is exerted on the vessels which are termed as blood pressure. Blood pressure is divided into two types, i.e., systolic blood pressure and diastolic blood pressure. Systolic B.P. is the maximum blood pressure in the vessels, and it occurs during the phase of contraction of heart while diastolic is the minimum blood pressure in the vessels and it is during the phase of relaxation of heart chambers.

When systolic blood pressure is measured the blood vessels are contracted while when the diastolic blood pressure is measured, the blood vessels are relaxed.

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The range of systolic blood pressure is 90 to 120 mmHg in the adults, 100mmHg in the school going age children (6 to 9 years) and 95 mmHg in the infants. Diastolic blood pressure ranges from 60 to 80 mmHg in the adults, 65mmHg in the school-age children and 65 mmHg in the infants.

Systolic blood pressure increases with the enhancing age while diastolic blood pressure decreases with the enhancing age and thus pulse pressure is widened.

With exertion, increasing fluctuations are observed in systolic blood pressure because the heart has to contract forcefully to meet the increased demand for blood and oxygen supply. Comparatively, fewer fluctuations are observed in the diastolic blood pressure. When the diastolic blood pressure is said to be increased on repetitive readings, it denotes heart failure.

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While you measure the blood pressure with a sphygmomanometer, the point at where you start hearing the pulse , it is systolic blood pressure while at the point where the pulse sound disappears, is diastolic blood pressure.

Contents: Difference between Systolic Blood Pressure and Diastolic Blood Pressure

Comparison Chart

Basis Systolic blood pressure Diastolic blood pressure
Definition It is the pressure exerted by blood in the blood vessels when heart contracts and pumps the blood in the vessels. It is pressure exerted by blood to the blood vessels when the heart is relaxed, and blood is filled within the heart chambers.
What is It is the maximum pressure of blood. It is the minimum pressure of blood.
Normal range in adults Its normal range is 90 to 120 mmHg in the adult. Its range is 60 to 80 mmHg in the adults.
Normal value in children In infants, its normal value is 95 mmHg while at the age of 6 to 9 years, the normal value is 90 mmHg. Its normal value is 65 mmHg in the infants and children less than 9 years of age.
Relation with age Systolic blood pressure increases with age. Diastolic blood pressure decreases with age.
Phases of heart  It is the pressure during the systolic phase of the heart. It is the pressure during the diastolic phase of the heart.
Relation with exertion During exertion, more fluctuations are observed in systolic blood pressure. During exertion, fewer fluctuations are observed in the diastolic blood pressure.
Measurement with a B.P. app. It is the pressure at the point where you start appreciating the pulse via stethoscope when measuring with a sphygmomanometer. It is the pressure at the point where the pulse disappears when you measure B.P. with a sphygmomanometer.

What is Systolic Blood Pressure?

Systolic blood pressure is the pressure created in the blood vessels when the heart undergoes the systolic phase, i.e., heart contracts and pumps the blood in the body. It is the maximum pressure of blood in the vessels. Its normal range is 90 to 120 mmHg in the adults while 95 mmHg in the infants and 90 mmHg in children. As we know, the heart has four chambers. Two atria and two ventricles. Both atria are filled with blood when blood comes from the whole body through superior and inferior vena cava, and then it is transported to lungs for oxygenation, and then via ventricles, it is pumped to the whole body. The phase of contraction of the heart is called the systolic phase and the pressure during the phase of systole in the blood vessels is actually the systolic blood pressure. Systolic pressure increases with the enhancing age. When the systolic blood pressure is above 130 mmHg on three repetitive readings on different occasions, the patient is labeled as class 1 hypertensive while when it is above 140 mmHg, the patient is class 2 hypertensive. Blood pressure is measured with a sphygmomanometer. Two methods are used, via palpation and via auscultation with a stethoscope. The point at which you start appreciating the pulse via stethoscope, it is the systolic blood pressure

What is Diastolic Blood Pressure?

It is the pressure in the blood vessels during the relaxation of heart chambers when the heart is filled with blood. It is the minimum pressure of blood. The normal range of diastolic blood pressure is 60 to 8it0 mmHg in the adults while 95 mmHg in the children and infants. While measuring the blood pressure via a B.P. apparatus and stethoscope, it is the blood pressure at the point where the pulse disappears, and you appreciate it via stethoscope. The fluctuation in the diastolic blood pressure is less when you are doing heavy work, and if the value of diastolic blood pressure is always increased on repetitive readings on different occasions, it denotes heart failure. If the value of diastolic blood pressure is subtracted from systolic blood pressure, the resulting value is called as pulse pressure. There is an increase in pulse pressure with the advancing age.

Key differences

  1. Systolic blood pressure is the pressure in the blood vessels when the heart contracts while diastolic blood pressure is the pressure measured when the heart
  2. Systolic blood pressure is the maximum pressure of blood while diastolic blood pressure is the minimum pressure of blood.
  3. Systolic blood pressure increases with the enhancing age while diastolic blood pressure decreases with advanced
  4. The normal range of systolic blood pressure is 90 to 120 mmHg while that of diastolic blood pressure is 60 to 80 mmHg.
  5. When you are doing heavy work, more fluctuation in the systolic blood pressure while less fluctuation in the diastolic blood pressure.
  6. Systolic blood pressure is the pressure of blood during the systolic phase of the heart cycle while diastolic blood pressure is the pressure measured during the diastolic phase of the heart

Conclusion

Systolic and diastolic blood pressure both are the types of the pressure of blood in the vessels. Both have different ranges and relation to the phases of heart cycles. It is mandatory to know the differences between both types of blood pressure. In the above article, we learned the clear differences between systolic and diastolic blood pressure.

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