Systole and diastole

Systole and diastole are two stages of the cardiac cycle. Systole is the contraction phase of the heart, where blood is pumped into the vessels, and diastole is the relaxation phase, which allows blood to enter the heart..

In a normal adult, the average systolic pressure is 120 millimeters of mercury (mmHg), while the diastolic is 80 mmHg.

Diastolic pressure occurs early in the cardiac cycle. It is the minimum pressure in the arteries when the pumping chambers of the heart fill with blood. Systolic pressure occurs at the end of the cardiac cycle, when the ventricles contract.

Blood pressure reading

The blood pressure reading is measured in millimeters of mercury (mmHg) and is supplied in two numbers.

The highest number is systolic blood pressure reading, representing the maximum pressure exerted when the heart contracts.

The lowest number is the diastolic blood pressure reading, which represents the minimum pressure in the arteries, when the heart is at rest.

So if the doctor says that your pressure is 120 by 80, it means that in systole it is 120 mmHg and in diastole it is 80 mmHg.

Regarding the heartbeat, which can be heard with a stethoscope, the first beat marks the onset of systole, and the second is the onset of diastole..

Normal and Abnormal Systolic and Diastolic Pressure Values

In children, the systolic measurement ranges from 95 to 100 mmHg and in adults it ranges from 90 to 120 mmHg. The diastolic measurement is approximately 65 mmHg in children, and in adults it ranges from 60 to 80 mmHg.

In cases of abnormality, the following numbers are identified in adults:

• Hypotension: if the systolic reading is less than 90 mmHg and / or the diastolic reading is less than 60 mmHg;
• Prehypertension: if the systolic reading is 121 to 139 mmHg and the diastolic reading is 81 to 89 mmHg;
• Stage 1 hypertension: if the systolic reading is 140 to 159 mmHg and the diastolic reading is 90 to 99 mmHg;
• Stage 2 hypertension: if the systolic reading is 160 mmHg and the diastolic reading is 100 mmHg.

It may interest you to know about HDL cholesterol and LDL cholesterol.