Causes

In most cases, low blood pressure is due to harmless causes. Many people have a predisposition for low blood pressure. There are various mechanisms in our body that intervene when blood pressure is too high and reduce it again.

In people with a predisposition to low blood pressure, these mechanisms are often more pronounced, so that the blood pressure is lowered more than necessary. Conversely, this can also happen in people with predisposed high blood pressure. Young and slim women are often affected by low blood pressure.

Especially unathletic women often suffer from low blood pressure. They often do not have the so-called orthostasis reaction adequately. Orthostasis means the upright posture of the body.

Young women often feel dizzy after getting up from a sitting or lying position. While sitting, a lot of blood accumulates in the legs. Normally, the nervous system of the body’s sympathetic nervous system ensures that the heart rate is increased and the blood pressure rises during and after getting up so that the blood can be transported sufficiently to the organs and especially to the brain against gravity.

If this reflex is insufficiently developed, the brain may be temporarily undersupplied with blood, which can cause short-term dizziness or blackness. Although the sympathetic nervous system ensures that the heart rate increases, the blood pressure still drops. Of course, this is not a serious undersupply of blood to the brain.

Too low blood pressure can also be caused by a reduced resistance of the blood vessels, a too low amount of blood, an insufficient pumping function of the heart, as well as a reduced return flow from the blood to the heart. In the short term, blood pressure can also drop in the event of a gastrointestinal infection, as a lot of fluids and salts are lost through vomiting and diarrhoea. The loss of salts further increases the loss of fluid, as salts normally ensure that fluid is absorbed.

That is why it is important to drink a lot in case of an acute infection. Illnesses can also lead to low blood pressure. These include above all hypothyroidism or an underfunction of the parathyroid gland.

Patients with varicose veins, i.e. bulging of venous blood vessels in the legs, can have more blood in their legs, which can also lead to low blood pressure. Wearing compression stockings helps to counteract this. If people with high blood pressure are given too high doses of antihypertensive drugs, such as the frequently used water tablets, this can also lead to low blood pressure.

Also a strong blood loss leads to low blood pressure. This can also occur as part of a gradual process, for example when blood is chronically lost via the stool. In addition to the causes already mentioned, heart failure or a heart valve defect can also cause too little blood to be pumped into the body’s circulation, resulting in a drop in blood pressure.

During pregnancy, blood pressure is typically lowered. This occurs in the first six months of pregnancy. This is due to a redistribution of the blood volume, since during pregnancy the child must also be supplied with blood via the placenta.

The pregnancy hormone progesterone ensures that the blood vessels are dilated. As a result, a lot of the blood accumulates in the legs according to gravity and the blood pressure drops. In the last third of the pregnancy, mechanisms that raise and normalize blood pressure then start working again.However, the blood pressure must not drop too much during pregnancy, otherwise the growing child cannot be supplied with sufficient blood.

This can occur, for example, if the child presses on the inferior vena cava in the uterus. This is a large vein through which the blood is transported back to the heart. Younger children are not usually affected by low blood pressure.

If the children then reach puberty, many circulatory problems occur. This is especially the case with slim girls. During puberty the hormone balance of the body changes and strong growth occurs.

In most cases, the circulatory reactions in adolescents are an orthostasis reaction as already explained, i.e. the blood pressure drops after getting up and the brain is not supplied with sufficient oxygen blood for a short time. Approximately 20 percent of all adolescents suffer a brief circulatory collapse before the age of 15. If the low blood pressure is caused by an illness, it is called secondary hypotension.

The most common cause is hypothyroidism. Hypothyroidism can be congenital or acquired. A family history of hypotony can be observed.

Since iodine is needed to produce the thyroid hormones, an iodine deficiency can also trigger hypothyroidism. The thyroid gland increases many metabolic processes. If the thyroid gland is now underactive, the metabolism slows down so that both physical and mental performance decreases.

The lack of drive causes blood pressure to drop. However, those affected also feel tired, unable to cope with stress, are sensitive to cold, suffer from hair loss and constipation and gain weight. Often the psyche also suffers from the disease.

However, not all of these symptoms need to be present in a patient. After active sports units, a drop in blood pressure can lead to symptoms such as headaches, dizziness, visual disturbances, etc. Very often the cause is a lack of fluid in the body.

Several liters of body fluid including electrolytes can be lost through increased sweating. A lack of drinking during the sport unit leads to a drop in blood pressure. It is also possible, however, that the condition is caused by excessive muscle training.

Usually the first thought of a physician is that an unhealthy diet can cause arterial hypertension. For example, a diet high in fat, salt and fiber plays a major role in this case. In addition, the fructose from many types of fruit attacks the vascular wall, which in the long term can lead to arteriosclerosis and hypertension.

But also in connection with a low blood pressure the nutrition can be. After eating a meal, low blood pressure can develop. This is caused by a pathologically increased amount of blood being drawn from the gastrointestinal tract during the digestive process.

As a result, the blood circulation is concentrated in the digestive tract, whereas the central cardiovascular system (heart, brain) is undersupplied with blood. Often, it is precisely people who suffer from this postprandial hypotension who are otherwise suffering from arterial hypertension (high blood pressure). Besides a connection with food intake, an overdose of antihypertensive drugs should be considered.

In the presence of manifest postprandial hypotension, small doses of medication should be taken with food intake. Pronounced consumption of alcohol can, in principle, lead to a temporary low blood pressure. This is caused by the vasodilatory effect of alcohol.

This can lead to typical symptoms such as reddening of the face. It is important to know that the blood pressure-lowering effect is only temporary. On the contrary, in the case of a manifest alcohol addiction the suffering of arterial hypertension can be aggravated.

Since increased emotions usually occur during alcohol consumption, vasodilatation can very quickly lead to vascular contraction. In addition, alcohol-induced increased blood pressure-increasing hormones are released in the brain. Alcohol consumption should therefore be limited to 10 to 20 grams (women) and 20 to 30 grams (men).

Even a small beer contains between 10 and 15 grams of alcohol!The consumption of alcohol usually results in a high intake of calories, which in the long run causes high blood pressure. Increased affective and impulsive effects also increase the heart rate. This, in combination with the increased blood pressure in alcoholism, can overload the heart.

In principle, young age can also lead to low blood pressure. This is usually because younger people are very thin in some cases. Especially in adolescence the body is faced with the challenge of growing fast.

The young people are relatively thin. The blood pressure is therefore usually lower than in adults. Up to about 20% of all children up to the age of 15 suffer a collapse once or several times due to a circulatory weakness.

Orthostatic dysregulation is the most common cause. The so-called vasovagal syncope also occurs very frequently. In this case, after getting up, a pathological drop in blood pressure occurs and the blood in the lower extremities sinks.

In this case the brain is temporarily undersupplied with blood and a circulatory collapse can develop. In the context of an iron deficiency, low blood pressure can occur. A pronounced iron deficiency can lead to anemia.

This occurs because iron is needed for the formation of blood cells in the bone marrow. Thus, if the formation is reduced, blood volume may be restricted, resulting in hypotension. Since women in particular often suffer from iron deficiency (for example, due to blood loss during menstruation), this constellation of findings is frequently found in gynecology. Blood pressure can be effectively lowered by weight reduction. Unfortunately I do not know the exact medical background.