Low blood pressure: values and causes

Low blood pressure – lowest and most dangerous levels

Diastolic – mmHg Systolic – mmHg

Low < 60 < 90

Normal < 80< 120

Prehypertension < 80 120/129

Hypertension

First degree 80-89 130-139

Hypertension

Second degree ≥ 90 ≥ 140

Source: www.heart.org

When to worry?

The normal blood pressure is 120/80, the lower limit is 90 for the upper value and 60 for the lower value, if they are below, one speaks of low pressure.

Dangerous values are below 60/40.

Types of low blood pressure

1) Postural or orthostatic hypotension.

This is a sudden drop in blood pressure when raised from a sitting or lying position.

Adequate blood supply to the organs depends on three factors:

1. A strong heart, because it needs to pump blood throughout the body,
2. arteries and veins that may narrow (vasoconstriction),
3. A sufficient amount of blood and fluid inside the blood vessels.

Pressure regulation depends on the cardiovascular system and the autonomic nervous system.

When a person rises from sitting, pressure receptors (baroreceptors) in the carotid arteries and in the aorta detect a slight decrease in pressure.

Gravity pulls blood down into our legs every time we stand.

Almost simultaneously, the sympathetic system is stimulated and the body balances the pressure:

1. By increasing the heart rate,
2. By narrowing the blood vessels.

This process serves to increase blood pressure.

In people with orthostasis syndrome, this balancing mechanism does not work and blood pressure drops. This causes dizziness, insecurity in the head, visual disturbances and even loss of consciousness.

The pressure drop is:

• At least 10 mmHg for diastolic pressure,
• At least 20 mmHg for systolic pressure.

Orthostatic hypotension usually lasts a few seconds or a few minutes. If it lasts longer, it may be a sign of a more serious problem.

Orthostasis syndrome can occur for a variety of reasons, including:

• Dehydration – causes a drop in circulating blood volume. It may be due to:
  • Fever
  • Vomit
  • Reduced fluid intake,
  • severe diarrhea,
  • Intense physical exercise,
  • Excessive sweating.
• immobility – prolonged bed rest,
• Pregnancy
• Parkinson’s disease,
• diseases of the endocrine system, such as: diabetes, adrenal insufficiency and thyroid disease,
• Some heart diseases can lead to low blood pressure:
  • bradycardia (low heart rate),
  • malfunction of the heart valves, the filling of the ventricle of the heart is insufficient,
  • Heart failure
  • Heart attack, can lead to extensive damage to the heart and reduce blood pumping power.
• Intense heat,
• Some neurological disorders.

Many medications can attempt postural hypotension, in particular:

1. Those used to treat hypertension, – diuretics, beta-blockers, calcium antagonists and ACE inhibitors,
2. Antidepressants
3. Medications for the treatment of erectile dysfunction (sildenafil).

Orthostase is common in the elderly, with more than 20 percent of people over the age of 65 suffering from the condition. This pathology can also affect young or healthy people who suddenly rise after prolonged sitting cross-legged or after working in a squatting position for a while.

2) Postprandial hypotension

Postprandial hypotension is a sudden drop in blood pressure after eating. Older people are particularly affected, whose blood pressure regulation is slower due to rigid artery walls.

After eating, a large amount of blood floods the digestive tract. Usually, the body counters this phenomenon with an increase in heart rate and narrowing of blood vessels to maintain normal blood pressure.

In some people, this mechanism does not work and causes:

• Vertigo
• Weakness
• excessive sweating,
• feeling powerless,
• Falls.

Postprandial hypotension often affects people with high blood pressure or with diseases of the autonomic nervous system, such as Parkinson’s disease.

To reduce symptoms, it is necessary to reduce the dose of blood pressure medication and take smaller meals.

3) Neurologically-mediated hypotension.

This disorder causes a drop in blood pressure after prolonged standing. Signs and symptoms such as dizziness, nausea and fainting occur.

Neurologically-mediated hypotension mainly affects young people and appears to occur due to faulty communication between the heart and brain.

After standing for a long time, blood pressure drops and blood collects in the legs.

The body then tries to normalize the pressure through changes.

However, in people with neurologically mediated hypotension, the nerves in the left ventricle of the heart signal to the brain that arterial pressure is too high instead of too low.

As a result, the brain causes vasodilation and lower heart rate, eventually lowering blood pressure.

This leads to a greater accumulation of blood in the legs and less blood in the brain, resulting in lightheadedness and the risk of fainting.

4) Multisystemic atrophy with orthostatic hypotension.

This rare disorder (also called Shy-Drager syndrome) causes progressive damage to the autonomic nervous system, which controls involuntary functions, such as:

1. Blood pressure
2. Heartbeat
3. Respiration
4. Digestion.

Although this disease is associated with muscle tremors, slowed movement, problems of coordination, speech and incontinence, the main feature is severe orthostatic hypotension along with very high blood pressure when lying down.

Causes of decreased systolic and diastolic pressure

Some of the triggering causes are listed below:

• One of the most common factors is the lack of vitamin B complex, especially vitamin B12 and folic acid. The lack of these two essential nutrients in the body can lead to anemia and a drop in blood pressure.
• The blood vessels may dilate and arterial pressure may drop due to allergic reactions that cause skin itching, rashes or hives, difficulty swallowing, shortness of breath, etc.
• Anaphylactic shock – It is a reaction of the immune system to an antigen.
• The first symptoms may be: itching, hives and rash.
• Subsequently, bronchial spasm, difficulty breathing and very low blood pressure develop.
• There may also be intestinal discomfort, including: vomiting, abdominal cramps and diarrhea.
• During pregnancy, the body undergoes many changes, because it has to adapt to the different needs. As there are some hormonal changes and the circulatory system expands to provide blood to the fetus, there is a drop in blood pressure and palpitations. In the first twenty-four weeks of pregnancy, women suffer from low blood pressure. Arterial pressure stabilizes after birth.
• Low blood pressure can also result from side effects of some medications such as antihypertensive drugs, antidepressants, diuretics, beta-blockers, etc.
• Also, diabetes is responsible for hypotension, because this disease damages the autonomic nervous system. If the nerves are damaged, the blood vessels find it difficult to adapt to this change and low blood pressure occurs.
• Dehydration is another reason why blood pressure drops below normal. If the body is dehydrated, there is a drop in blood volume. This condition (also called hypovolemia) can become dangerous if not treated in time.
• Micturition syncope is a condition in which the person faints if he makes a special effort during defecation or urination. Due to excessive exertion, the vagus nerve is stimulated to produce acetylcholine. This chemical widens blood vessels and lowers blood pressure, thus depriving the brain of blood.
• Blood loss and internal hemorrhages in organs from trauma or injury cause a serious drop in blood pressure. This disorder can also occur with excessive menstruation. Blood pressure returns to normal when the problems are treated.
• Septicemia or sepsis (which is caused by pathogenic germs in the blood that lead to infection) is also a triggering factor for a drop in blood pressure. This condition can increase toxins in the blood and damage blood vessels, resulting in septic shock that can be fatal.
• Damaging substances in the blood can reduce the pumping power of the heart, resulting in a drop in blood pressure.
• The thyroid gland produces hormones that interfere with the control of various bodily functions, including heart rate and blood pressure.
• In particular, hypothyroidism can lead to hypotension.
• Adrenal insufficiency – It is a disease of the adrenal glands characterized by reduced production of hormones:
  1. Cortisol

Cortisol has many functions, including regulating blood pressure.

• Neurogenic shock
• Occurs in people with paraplegia or quadriplegia.
• Hypotension is the result of lack of activity of the sympathetic nervous system below a lesion of the spinal cord and is provoked by the dilation of peripheral arteries.
• Discontinuation of corticosteroids
• After cortisone administration of at least 2 weeks, symptoms may occur after discontinuation of therapy, including acute adrenal insufficiency.
• This disorder is characterized by: nausea, vomiting, dehydration, weakness and hypotension.
• During treatment, the axis of the hypothalamic-pituitary-adrenal gland is blocked, at the end of treatment it begins to work again, but only gradually.
• It takes 2-3 months to restore pituitary function, while it can take 6-9 months for cortisol production to be fully restored.
• Therefore, it is important that the discontinuation of therapy is slow and gradual.
• Ectopic pregnancy
• In ectopic pregnancy with tubular rupture, intraperitoneal bleeding occurs and the symptoms are vasovagal syncope:
  1. Syncope
  2. decrease in blood pressure,
  3. tachycardia (accelerated heartbeat) due to hypervolemia,
  4. Acute pain.
• Malnutrition
• People with anorexia nervosa have a slowed heartbeat as well as low blood pressure.
• Nervous bulimia leads to an imbalance of electrolytes, which causes irregular heartbeat, heart failure and severe hypotension.

Sudden drop in blood pressure

In the following, situations are mentioned that can cause a sudden drop in arterial pressure:

1. A person bedridden for a long time, who then takes an upright position, triggering an orthostasis syndrome,
2. A woman with low blood pressure in the first 24 weeks of her pregnancy,
3. An injury or accident that results in greater blood loss,
4. A person taking antihypertensive drugs, drugs used to treat heart disease, Parkinson’s disease, erectile dysfunction or antidepressants,
5. A patient suffering from endocrine problems such as Addison’s disease, hypoglycemia, diabetes, parathyroiditis, hypothyroidism, etc.,
6. Severe septicaemia,
7. Anaphylaxis
8. Dehydration
9. Decreased blood pressure after eating, known as postprandial hypotension.

When is blood pressure too low?

If the systolic blood pressure is 80 and the diastolic blood pressure is 50, these values are far below the normal level. For example, if there is a sudden drop in systolic blood pressure from 130 to 90, you may feel dizzy and you may become unconscious. Therefore, a sudden drop in arterial blood pressure can be life-threatening.

Symptoms of low blood pressure after running (physical activity)

Dehydration is the most common cause of hypotension after physical activity.

If the body loses a lot of fluid, dehydration occurs.

If you pay attention to adequate hydration, you can prevent the drop in blood pressure after exercise and thus also allow the body to perform better.

An adequate supply of fluids before training is a good prerequisite to avoid dehydration or at least reduce the effects of dehydration.

What to do? Natural remedies for low blood pressure

Drink a lot

If a person suffers from dizziness due to dehydration, rehydration is of particular importance and one should drink plenty of water. The increase in the amount of fluid increases blood volume, and blood pressure increases.

Compression stockings

These elastic stockings help raise blood pressure by preventing blood accumulation in the legs, thus improving blood circulation in the body.

Getting up slowly

If you feel dizzy when standing up from lying down, it is best to return to the starting position and wait until the dizziness has passed. People suffering from orthostatic hypotension should always stand up slowly from a resting position, especially when they get out of bed in the morning.

In case of dizziness or malaise, it is especially important to lie down and ask someone to keep their legs up for a moment.

Thermae

Those who suffer from low blood pressure should be careful in thermal baths, because the warm water can increase the symptoms.

Smoke

Smoking can increase blood pressure, but it is always recommended to stop smoking because of the numerous side effects.

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