By: Prof. Dr. Şükrü Akyüz

The blood exerts a certain amount of pressure on the vessel wall. This pressure provides the necessary driving force for the flow of blood. When the heart contracts to pump the blood, the vascular width increases as the pressure increases, and when the heart relaxes, the vascular width decreases and returns to its previous state. High blood pressure, or hypertension as it is called in medical language, is the name given to this pressure applied to the vessel wall being higher than normal. It is also often referred to as blood pressure among non-medical people.

Two numbers are used to express blood pressure: The first number is always greater than the second number, hence the name hypertension (systolic blood pressure). This is the value when the heart is pumping the blood, when the vascular pressure increases temporarily. The second number is the value when the heart relaxes and is called small blood pressure (diastolic blood pressure); it indicates the basal pressure inside the vessel. Technically, for example, it is said to be 110/80 mmHg, but in everyday use it can also be shortened to “11/8”.

A large blood pressure greater than 14 or a small blood pressure greater than 9 indicates high blood pressure. In hypertension, only the upper blood pressure, only the lower blood pressure or both can be high. By the way, there are also sources that accept the hypertension limit as 13/8, not 14/9. In other words, the limit values are controversial in the medical community.

In some people, hypertension is caused by causes such as stenosis of the renal arteries, hormonal disorders and severe stress. However, in most people, the exact cause is not clear. It is thought to be caused by the interaction of genetic and environmental factors.

In hypertension; either the vessel contracts due to certain chemical active substances and the pressure increases because it compresses the blood inside, or the pressure increases because the blood volume inside the vessel is excessive even if the vessel is of normal width. Usually, these two mechanisms work together.

Why hypertension is important

  • If hypertension is not controlled, over the years organs are exposed to high blood pressure and suffer damage. For example, the heart builds muscle and thickens its walls in order to overcome the high pressure in order to be able to send the blood through. This adaptation, which initially works well, unfortunately hardens the heart in the long term, impairs its relaxation and reduces the volume of the left ventricle that can be filled with blood. In the most advanced stage, the heart becomes tired, weak and enlarged, resulting in heart failure.

  • Hypertension also predisposes to fat deposition in the vessel walls. Hypertension is therefore an important risk factor for vascular stenosis. Stenosis can occur not only in the heart, but anywhere, especially in the legs.
  • It can also cause cracks in the blood vessels and lead to sudden blockages. This can result in a heart attack in the heart or a stroke in the brain. Hypertension can also indirectly cause stroke by causing a rhythm disorder in the heart called atrial fibrillation (AF). In some patients, a clot that forms in the heart in this arrhythmia can travel through the bloodstream to the brain vessels and block them.
  • Hypertension can also cause aneurysms (ballooning) to form in the brain vessels or burst if the ballooning is already present. This is an important cause of cerebral haemorrhage. Such an aneurysm can also occur in the aorta. This can also burst if it becomes too large and can be fatal.
  • Hypertension can damage the eye and kidney vessels and impair the function of these organs.

In summary, although any organ can be affected by hypertension, the heart, brain, aorta, eyes and kidneys are particularly vulnerable. However, it is important to remember that these are complications that can occur if hypertension is not controlled. It is therefore very important to follow a healthy lifestyle, as summarised below, to maintain normal blood pressure. If these lifestyle changes do not work or if blood pressure values are too high even at the beginning, blood pressure medication (antihypertensive medication) is started. The medication normalises blood pressure by acting on the mechanisms that increase blood pressure. In other words, they either inhibit the effects of chemical substances that constrict the blood vessels and keep them dilated, or they act on the kidneys so that excess fluid in the blood vessels is excreted in the urine.


How to recognise high blood pressure?

When your blood pressure rises, symptoms such as headache, dizziness, fatigue, chest pain, shortness of breath and irregular heartbeat may occur. However, most blood pressure patients actually have no symptoms. In other words, the absence of complaints does not mean that blood pressure is normal. The definitive way to determine whether blood pressure is high or not is to measure it with a blood pressure monitor.

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What level of blood pressure should you go to the emergency room?

If the blood pressure is elevated, the measurement value is not the main criterion for a visit to the emergency department. What is more important is whether there are any accompanying complaints of hypertension. If the blood pressure exceeds the normal limit value and any of the following are present at the same time, you should go to the emergency room without waiting:

  • Chest pain
  • Shortness of breath
  • Visual impairment
  • Speech impairment
  • Severe headache
  • Loss of balance
  • Numbness, loss of sensation or strength in
  • the limbs
  • Fainting

Whether blood pressure is measured on the left or right arm?

If you are taking blood pressure for the first time, both arms should be measured. One arm is usually slightly higher than the other; this is normal. Whichever arm has the higher reading, that arm is always measured, because that is where the actual blood pressure reading is taken. However, a difference of more than 20 mmHg between the arms is not normal (e.g. left arm 155/75 mmHg, right arm 120/70 mmHg; i.e. 155-120 = 35). In this example, the higher value, i.e. the value on the left arm (155/75 mmHg), is considered the true blood pressure. In such cases, the blood pressure in the right arm may be falsely low because of reduced blood flow due to stenosis in the right arm. Therefore, various imaging tests (Doppler ultrasound, computed tomography, etc.) should be performed to determine whether the patient has a stenosis in the right arm

What should be considered when measuring blood pressure?

  • Devices that measure at the wrist are more likely to be inaccurate. Therefore, prefer automatic devices that measure from the upper arm

  • If you are stressed, anxious, in pain or in need of the toilet, your blood pressure may be temporarily high. Repeat the blood pressure measurement when these symptoms have passed.

  • Do not exercise, smoke, drink caffeine-containing beverages such as tea and coffee before the measurement.
    Do not take a measurement while wearing clothes that are too tight on your arms.
    Rest for a few minutes before the measurement.

  • Sit comfortably with your back straight.
    Place your arm freely on an object such as a coffee table so that the cuff of the blood pressure monitor (the part that wraps around the arm and inflates) is at the same level as your heart.

  • Do not talk while taking a measurement. Take at least two measurements; take the average of the two. If you have an anxious personality, the first measurement may be too high due to stress. Therefore, consider the average of the 2nd and 3rd measurements. Take a 1-2 minute break between measurements.