Definition
Low blood pressure (hypotension) is defined as a blood pressure of less than 105/60 mmHg. The standard value of blood pressure is 120/80 mmHg. The first value of blood pressure occurs during the ejection phase of the heart, the so-called systole.
Here the heart pumps blood into the body. During this phase a higher pressure must be built up. This is also called the systolic value.
The second value, the diastolic value, corresponds to the diastole of the heart. In this phase, the heart relaxes so that it can fill up with enough blood. Low blood pressure is not really a disease. On the contrary – it is believed that low blood pressure has a prognostically beneficial effect. However, too low blood pressure should not be aimed for.
When does low blood pressure become dangerous?
By definition, blood pressure values of less than 105/60 mmHg are medically considered to be too low. However, since symptoms that occur are not always necessarily linked to certain threshold values, it is difficult to determine when low blood pressure becomes critical for the person concerned. Low blood pressure levels have a potentially protective effect.
When a therapeutic indication exists is controversially discussed among physicians. Some physicians assume a treatment indication for blood pressure values below 90/60 mmHg. Blood pressure can become dangerous if there are several complications. Particularly important is the occurrence of syncope with consecutive falls, which can have far-reaching consequences for the affected person. Also a strong tiredness during the day in case of sleep disorders and the general decrease of the performance capacity can strongly restrict the private and working life of the affected person.
At what blood pressure do you faint?
The point at which a person faints is very different from person to person, depending on gender and situation. In women, hypotension is considered to be present from values of 100/60 mmHg, whereas in men it is only present from values of 110/70 mmHg. In principle, one can also faint at values above this reference, for example, when there is a rapid drop in blood pressure.
Thus, the occurrence of fainting also depends on the normal blood pressure value of a person. Roughly speaking, blood pressure values around 70/40 mmHg often lead to fainting incidents. In many people with low blood pressure, the body is already accustomed to this condition and has adapted so that they do not experience any symptoms.
Typical symptoms in patients with low blood pressure are circulatory problems. These include dizziness in particular. Dizziness occurs mainly in the morning and when getting up from lying down or sitting.
Sometimes you also get ringing in your ears and flickering before your eyes or you get black and faint. Some notice their low blood pressure also by a trembling of the hands. Fatigue and poor performance can be associated with low blood pressure.
Those affected often also suffer from concentration problems. The body tries to control the low blood pressure by increasing the heart rate, among other things. In this way, it tries to ensure that all organs can be adequately supplied despite the low blood pressure.
Due to the increased heart rate, those affected can feel their heart beating. Cold hands and feet are also a frequently observed symptom. Blood pressure values should be in the range of 120 to 80 mmHg in healthy people.
The normal pulse (heart rate) in a healthy person is 70, in athletes the resting pulse can be up to about 50 beats per minute. If low blood pressure is combined with a high pulse rate, this does not usually mean that there is a serious illness behind it. On the contrary, this combination is very common.
The medical background of this condition is that the body undertakes a compensatory mechanism in case of low blood pressure. In particular, it tries to compensate for the reduced blood volume in the vascular system when blood pressure is low by increasing the heart rate and, as a rule, also by increasing the stroke volume. Depending on the situation, this special combination can also occur.
Therefore, it is recommended that the values be determined by repeated measurements. The resting pulse rate should be determined in the morning.However, if a pulse of more than 100/minute and hypotension (especially systolic blood pressure below 90 mmHg) is present during multiple measurements, there may be a more serious cause. If you are more interested in this topic, the blood pressure drops as a result of restricted heart function and a low blood pressure develops.
The primary cause is not in the peripheral vascular system, but in the heart itself. In the case of incipient heart failure, the heart first tries to keep the blood pressure high by increasing the heart rate and stroke volume. This mechanism does not take effect permanently due to a shortened diastole and an overall increasing heart enlargement with decreasing contractility.
At some point in time, the heart can no longer maintain its heart rate and stroke volume in the event of progressive heart failure (cardiac insufficiency). As a result, pulse and blood pressure drop. The situation is similar with certain cardiac arrhythmias.
In these cases, no continuously targeted blood ejection can take place, which is why pulse and blood pressure can drop. A very typical combination of low blood pressure and headaches often occurs on hot summer days. Here the body loses a lot of fluid volume through sweat.
In addition, staying in the sun (especially in the time between 11 a.m. and 3 p.m.) can cause heat stress to the head. If low blood pressure then occurs, the blood flow to the brain is temporarily reduced. This reduced supply of oxygenated blood to the brain can manifest itself as a pulsating, often stabbing headache.
Typically, this condition is a reversible pathomechanism. The headache can disappear if the patient drinks a sufficient amount of water and, if necessary, avoids excessive exposure to sunlight on the head. Exercise is generally beneficial in cases of low blood pressure due to a lack of volume.
This increases the circulation of the blood. In addition to typical symptoms of low blood pressure, low blood pressure can also be associated with dizziness. Dizziness, which is often accompanied by visual disturbances, is one of the most common symptoms of low blood pressure.
As with headaches resulting from low blood pressure, dizziness is caused by an undersupply of blood to the brain. The dizziness is also often accompanied by ringing in the ears. The potential risk of falling is particularly dangerous in the case of dizziness due to low blood pressure.
Especially for pregnant women and elderly people, hypotension-induced falls can have far-reaching consequences. In pregnant women, traumatic damage to the fetus can occur. Older people are predestined for bone fractures such as the femoral neck fracture due to reduced bone density and frequent osteoporosis.
Dizziness very often occurs in the case of a so-called orthostatic dysfunction. In this case, the change in the body’s position from lying down to standing causes the blood to sink into the lower extremity. The brain is temporarily undersupplied, which can result in dizziness and impaired vision.
In the course of hypotension, there is often a decrease in performance and lack of concentration due to fatigue. This constellation is based on a generally reduced supply of certain organs, which ensure the body’s performance. These include above all the brain, but also the musculature and others.
However, it is precisely these organs that require a sufficient supply of oxygen and nutrients. When blood pressure is low, the supply of these important substances may be inferior to the demand, resulting in reduced performance. In addition, low blood pressure can also lead to associated sleep disorders.
The development of fatigue as a result of this pathomechanism also appears possible. A lack of sleep or sleep that is not very restful can lead to depressive moods in addition to pronounced daytime tiredness. Therapeutic intervention is important here in order to maintain the ability to work and to avoid complications.
These can be accidents as a result of a microsleep, for example. Low blood pressure can lead to sensitivity disorders, especially in the distal sections of the fingers and toes and the acra (nose, ears). The cause is a reduced blood supply to these peripheral parts of the body, just like the feeling of cold.This leads to irritation of the neuromuscular function.
By sufficient movement of the fingers or toes the tingling should decrease. Flickering of the eyes as a result of low blood pressure is expressed by bright points of light in the field of vision, which can change their colors several times. The vision can be partially, but also distinctly restricted by these light stimuli.
The flickering of the eyes occurs for varying lengths of time. The cause of this is as yet unexplained. However, the eye flickering is probably a reaction to the reduced supply of the arteries of the eye. Frequently, other symptoms such as tiredness, headaches, and a feeling of cold in the fingers appear, making the diagnosis of hypotension probable.
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