Blood Pressure Basic Facts

WHAT IS BLOOD PRESSURE?

The pumping action of the heart must create enough force to push blood through the major arteries, into the smaller arteries, and finally into the tiny capillaries, where the porous walls permit fluid exchange between the blood and body tissue.

Several factors influence blood pressure:

The nervous system helps maintain blood pressure by adjusting the size of the blood vessels, and by influencing the heart’s pumping action. The kidneys assist in regulating blood pressure by adjusting mechanisms that change blood volume. For example, when blood flow to the kidneys is reduced, as would be the case in atherosclerosis, the kidneys set in motion action which raises blood pressure by expanding blood volume and constricting surrounding blood vessels.

Obesity is a contributing factor because excess body fat, especially abdominal fat, can precipitate hypertension. Another reason could be the extra miles of capillaries, through which blood must be pumped. Obesity may also trigger Sleep Apnea - a severe form of snoring, accompanied by breathing interruptions, which may trigger the development of high blood pressure.

Insulin resistance, which is associated with obesity, triggers the pancreas to produce more insulin in order to get glucose to the cells. High levels of insulin may signal the kidneys to retain sodium, precipitating the development of hypertension. This may explain why hypertension is 2 to 3 times more likely to occur in people with Diabetes Mellitus Type II.

Your blood pressure is determined by two factors - the force with which the heart pumps blood to the body, and the arteries’ resistance to blood flow. What we normally call "blood pressure" is actually the combination of these two types of pressure:

Systolic Pressure – The blood pressure measured in the arteries as the heart contracts and pumps blood into the blood vessels. This marks the maximum pressure in the arteries.
Diastolic Pressure - The blood pressure measured in the arteries between heart beats - when the heart relaxes. This marks the minimum pressure in the arteries.

The first, or higher number in your BP reading represents systolic pressure, and the second, lower number represents diastolic pressure.

The units of measurement are millimeters of mercury, representing the column of mercury used in blood pressure gauges ( ‘Millimeters of mercury’, is abbreviated to ‘mmHg’).

Hypertension simply means that the pressure the blood creates in the arteries is too high.  

HOE HOOG IS TE HOOG?

To ensure an accurate blood pressure reading:

• Do not drink coffee or smoke for 30 minutes before the blood pressure check.
• Before your blood pressure is checked, sit still for five minutes with your back supported and your feet flat on the ground. Try to rest your arm on a table at the level of your heart.
• Go to the bathroom prior to the reading. A full bladder can change your results.
  

Even if your systolic or diastolic readings are normal, only one of the numbers needs to be high for a diagnosis of Hypertension.