Risk factors
The Kompetenznetz Schlaganfall has also published a patient brochure on this topic: What can I do to prevent a stroke?
Theoretically, anyone can suffer a stroke – whether they are young or old. In principle, stroke is not a disease that only affects the “elderly”. Around one in four new stroke patients is of working age (P. U. Heuschmann et al. Schlaganfallhäufigkeit und Versorgung von Schlaganfallpatienten in Deutschland. Akt Neurol 2010; 37(7)), an estimated 5 % of them are even younger than 40.
In addition, people whose relatives have suffered a stroke are at an increased risk of stroke, as certain risk factors for suffering a stroke are hereditary.
Age and genetic conditions are therefore risk factors that cannot be influenced. Other risk factors that increase the likelihood of a stroke can be influenced by people. These risk factors include above all
High blood pressure
Smoking
Fat metabolism disorders
Overweight and lack of exercise
Diabetes / diabetes mellitus
Cardiac arrhythmia (atrial fibrillation)
High blood pressure
High blood pressure is also known as arterial hypertension. Arterial hypertension is defined as a permanent increase in systolic and diastolic blood pressure (upper and lower blood pressure values). Elevated values measured once or occasionally do not necessarily mean high blood pressure. Regularly elevated readings are decisive for the diagnosis.
The optimum blood pressure is 120/80 mm Hg (according to the WHO target values).
The threshold for arterial hypertension in adults is 140/90 mm Hg.
Hypertension can vary in severity depending on the level of blood pressure:
moderate hypertension: values that are permanently above 160/100 mm Hg
severe hypertension: values that are permanently above 180/110 mm Hg
High blood pressure is a significant risk factor for stroke, as it leads to narrowing and calcification of the blood vessels (arteriosclerosis). This is why patients with high blood pressure suffer strokes more frequently than people without high blood pressure. High blood pressure increases the relative risk of suffering a stroke by a factor of six to eight compared to a person who does not have high blood pressure. The level of high blood pressure plays a special role here, as the risk of stroke increases with the level of blood pressure. Treating high blood pressure, on the other hand, leads to a significant reduction in risk compared to untreated patients.
A major problem is that high blood pressure is still too rarely recognized. A person with high blood pressure usually does not notice it, because high blood pressure does not hurt. It is therefore important to have your blood pressure checked regularly and to initiate treatment if necessary. Everyone should know their blood pressure.
Smoking
Cigarette smoking is a significant risk factor for stroke. The risk of stroke increases with the number of cigarettes smoked per day and the number of years smoked. Compared to non-smokers, smokers have a 1.5 to 2 times higher relative risk of suffering a stroke. The negative effects of smoking are manifold:
Smoking promotes calcification of the blood vessels (arteriosclerosis).
Smoking leads to the release of the stress hormones adrenaline and noradrenaline via the nervous system and to a narrowing of the blood vessels. This in turn leads to high blood pressure. The constriction of the blood vessels restricts the supply of vital substances to the brain as, for example, not enough red blood cells can flow in the constricted “pipes”.
In addition, smoking reduces the amount of oxygen that the red blood cells can transport in the body. The amount of oxygen available to the brain (and other parts of the body) decreases. Due to the lack of oxygen, the brain signals the bone marrow to produce more red blood cells. The increased production of red blood cells leads to a “thickening of the blood” and the blood flow properties are disturbed. The blood is thicker and more viscous, making it harder to flow through the constricted blood vessels.
Smoking also makes the blood more likely to clot, in particular by increasing the stickiness of the blood platelets (thrombocytes). This increases the risk of clots forming in the blood. Finally, smoking leads to lipometabolic disorders.
So give up smoking in any case!
Quitting cigarette smoking leads to a significant reduction in the risk of stroke. Just five years after quitting smoking completely, your risk returns to that of a non-smoker.
Lipid metabolism disorders
Lipid metabolism disorders increase the risk of stroke, as blood fats are deposited on the artery walls and promote the development of vascular calcification (arteriosclerosis).
Cholesterol should be emphasized, as cholesterol levels above 240 mg/dl increase the risk of stroke by two and a half times. The cholesterol level should be below 200 mg/dl. This guideline value is particularly important if the “bad” part of cholesterol (the so-called LDL) is increased and the “good” part of cholesterol (the so-called HDL) is decreased.
Everyone should know their blood cholesterol level and, if necessary, treat it by changing their diet or taking medication. Diet has a major influence on cholesterol levels. As a guideline, the consumption of animal fats should be limited or replaced by vegetable fats. Sport and regular exercise also have a positive influence on blood lipid levels.
Smoking, however, has a negative effect on blood lipid levels.
Overweight and lack of exercise
What is considered “fat” or “skinny” is often enough determined by fashion and the zeitgeist. It is difficult to say what an individual’s ideal weight should be. Nevertheless, it is possible to determine which body weight corresponds to the statistical average for which height, brings with it a high life expectancy and promotes health.
Being overweight is defined as having too much body weight compared to your height.
This ratio is calculated using the so-called “Body Mass Index” (BMI). The BMI is calculated by dividing the body weight in kilograms [kg] by the square of the body height in meters [m²]. The recommended BMI depends on age and can be found in the table below.
BMI = body weight [kg] / height [m²]
| Age group in years | Desirable BMI [kg/m²] |
|---|---|
| Age group in years | Desirable BMI [kg/m²] |
| 19 – 24 | 19 – 24 |
| 25 – 34 | 20 – 25 |
| 35 – 44 | 21 – 26 |
| 45 – 54 | 22 – 27 |
| 55 – 64 | 23 – 28 |
| 65 | 24 – 29 |
Being overweight is a risk factor for many diseases. It leads to high blood pressure, puts a strain on bones and joints and increases the risk of developing diabetes. The relative risk of an overweight person suffering a stroke is one to two times higher than that of a person of normal weight.
Therefore: Get moving. This is one of the most important ways to lose excess weight. As a general rule, endurance sports make sense. Start slowly, but: get started!
Diabetes mellitus
Diabetes is an important risk factor for stroke. Diabetes is a collective term for many different forms of metabolic disorders which have in common that the sugar level in the blood is too high after eating and on an empty stomach. In patients with diabetes, the walls of the blood vessels are attacked. They thicken and this disrupts the patency of the blood vessels. The thickening of the vessel walls is also caused by hardening of the arteries (arteriosclerosis). The thickening of the vessel walls is exacerbated by all forms of diabetes, including so-called “adult-onset diabetes”.
The risk of suffering a stroke is two to three times higher for people with diabetes than for healthy people. Many people with diabetes do not initially realize that they have the disease. Diabetes does not hurt, which is why the disease is often only noticed late. Adult-onset diabetes is the most common form. Here too, only a known disease can be treated. Regular checks for the presence of diabetes are therefore advisable. Treatment can reduce the risk.
Cardiac arrhythmias (atrial fibrillation)
Cardiac arrhythmias are disturbances in the normal course of the heartbeat, or more precisely the excitation of the heart muscle. The heart then no longer beats regularly. One type of cardiac arrhythmia in particular, atrial fibrillation, means a significantly increased risk of stroke. The risk of stroke is at least five times higher in people with atrial fibrillation. Around 5% of all people with atrial fibrillation have a stroke every year. If, in addition to atrial fibrillation, other heart diseases such as cardiovascular disease (coronary heart disease) or cardiac insufficiency are also present, the risk increases by a factor of two to three. The presence of so-called rheumatic heart damage, which is caused by a streptococcal infection, is particularly serious. Atrial fibrillation with rheumatic heart damage increases the risk of stroke by a factor of seventeen. Data from scientific studies also suggests that older people with atrial fibrillation in particular are at an increased risk of stroke.
In people with atrial fibrillation, the irregular heartbeat can cause small blood clots to form in the heart (especially in the so-called atrium). These blood clots can then be pumped from the heart into the brain, where they block the cerebral vessels and thus interrupt the blood supply to the brain.
Atrial fibrillation is common: 2.3% of people between the ages of 40 and 65 suffer from it, and around 5.0% of people over the age of 65.
By feeling the pulse on the wrist, it is easy to determine whether the heartbeat is regular or not. An ECG can be used to detect many types of cardiac arrhythmia. Here too, many people are unaware that they have cardiac arrhythmia. Only an examination can provide certainty.
To prevent a stroke in people with atrial fibrillation, medication is used to thin the blood in order to prevent the formation of blood clots. These drugs are called anticoagulants. The best-known drugs for blood thinning are Markumar®, Warfarin® and Falithrom®. Aspirin® (ASA) also thins the blood, but works in a different way. Aspirin® belongs to the group of drugs known as platelet aggregation inhibitors.
