Why is diastolic pressure required

High blood pressure: limit values ​​for systole and diastole & classification of blood pressure values

Limits for systole and diastole

The blood pressure represents the pressure that prevails inside the vessels and is vital for the human circulation: Driven by the pumping power of the heart, blood constantly flows through our vessels. The blood flow is not even, but the blood is pumped through the body in bursts - with every heartbeat. In order to get into all vessels, including their smallest branches, the capillaries, the blood needs a certain pressure (= blood pressure). In addition to other ingredients, the blood primarily transports oxygen and nutrients to supply the cells in the body.

To determine the blood pressure, two values ​​are determined, the systolic and the diastolic blood pressure:

  • The systolic pressure (upper measured value) corresponds to the maximum pressure developed during the tension and expulsion phase of the left ventricle. The tension and expectoration phase is called systole. The systolic pressure is usually in the range of 110-130 mmHg.
  • The diastolic blood pressure (lower measured value) corresponds to the lowest pressure during the relaxation and expansion phase of the heart muscle. The phase between the greatest pressure development (systolic pressure) and the greatest pressure drop (diastolic pressure) is called diastole. During diastole, the heart chambers fill with new blood. Diastolic pressure is usually in the range of 80-89 mmHg.

The blood pressure is given in mmHg. 1 mmHg is the pressure that one millimeter (mm) exerts on a column of mercury (Hg). This corresponds to: 1 mmHg = 0.00133 bar.

Classification of blood pressure values

The blood pressure is individual and also depending on the situation. The level of blood pressure depends on various factors. Which includes:

  • The strength of the heart's activity, i.e. the pressure and pumping power of the heart per heart action - adapted to the respective physical load (during exertion and increased oxygen demand, for example, more blood has to be transported to the stressed organs / parts of the body in the same time as in the resting state, therefore a Increase in pressure and heart rate required)
  • The elasticity of the great vessels
  • The resistance, which is determined by the vessel size. The greater the flow resistance, the more pressure is necessary to push the blood through it
  • The signals of certain hormones and nerves (neurohormonal system)
  • The respective body position.

In the non-stressed state, a blood pressure value that does not exceed 120/80 mmHg is optimal. A value of no more than 129/84 is considered normal, 130-139 / 85-89 mmHg is considered a high normal value.

Blood pressure is slightly elevated if the measured values ​​are between 140-159 / 90-99 mmHg. With higher values ​​one speaks of moderately increased (160-179 / 100-109 mmHg) to severe high blood pressure (more than 180 / more than 110 mmHg).

According to the European guidelines for the prevention of cardiovascular diseases from 2016, systolic blood pressure values ​​of up to 150 mmHg can be tolerated in older age. In type 1 diabetes, systolic blood pressure values ​​below 130 mmHg and diastolic blood pressure values ​​below 80 mmHg should be aimed for. In type 2 diabetes, systolic blood pressure values ​​below 140 mmHg, diastolic blood pressure values ​​below 85 mmHg are recommended.