Low pressure

Generality

Low pressure is a condition characterized by lower resting values than normal. In numerical terms, an individual suffers from low blood pressure when his arterial pressure at rest falls below 90/60 mmHg.

Although less frequent than the most serious and worrying hypertension, low blood pressure (or hypotension ) is a rather common disorder, which is frequently associated with generalized fatigue, dizziness, a sense of fainting, confusion and blurred vision.

Low blood pressure can depend on various factors, including: genetics, constant physical activity, certain diseases, taking certain medications and pregnancy.

Generally, cases of hypotension sustained by pathological states, pharmacological intakes or pregnancy, as symptomatic and potentially dangerous, are worthy of the doctor's attention (NB: genetics and constant physical activity are responsible for slight pressure drops, without consequences and even benefits, in some cases).

Treatment of low blood pressure depends on the triggering causes; as a rule, symptom-free hypotension requires no specific therapy.

Brief review of what blood pressure is

Blood pressure, or arterial blood pressure, is the force that blood exerts against the walls of blood vessels, following the pump action performed by the heart.

Its value depends on various factors, including:

The force of contraction of the heart;
Systolic range, ie the amount of blood leaving the heart at each ventricular contraction;
Heart rate, ie the number of heartbeats per minute;
Peripheral resistances, ie resistances opposed to blood circulation from the state of constriction of small arterial vessels (arterioles);
Elasticity of the aorta and large arteries (the so-called vascular compliance);
Volemia, ie the total volume of blood circulating in the body.

Measured in millimeters of mercury (mmHg) and in a state of rest, the blood pressure is usually defined by the values of systolic or " maximum " pressure (it is the arterial pressure of when the heart contracts) and diastolic or " minimal " pressure ( is the arterial pressure of when the heart is relaxing).

In a healthy individual, resting blood pressure can have systolic values between 90 and 129 mmHg and diastolic blood pressure values between 60 and 84 mmHg.

According to the medical-scientific community, the optimal arterial pressure at rest is 120 (p. Systolic) / 80 (p. Diastolic) mmHg.

Curiosity

Blood pressure is one of the so-called vital signs, such as respiratory rate, heart rate, oxygen saturation and body temperature.

Arterial pressure values	Systolic / Diastolic
DANGEROUS LOW PRESSURE	<50/33 mmHg
TOO LOW PRESSURE	<60/40 mmHg
LOW PRESSURE	<90/60 mmHg
OPTIMAL ARTERIAL PRESSURE	<115/75 mmHg
ACCEPTABLE ARTERIAL PRESSURE	<130/85
PRE-HYPERTENSION	130-139 / 85-89 mmHg
STADIUM HYPERTENSION 1	140-159 / 90-99 mmHg
STADIUM HYPERTENSION 2	> 160 /> 100 mmHg
Consolidation of stages 2 and 3 (180/110 mm Hg) of hypertension, because the therapeutic approach is the same

What is low blood pressure?

Low blood pressure, or hypotension, is the condition characterized by lower resting blood pressure values than normal.

In numerical terms, those suffering from low blood pressure have arterial pressure at rest below 90/60 mmHg .

Low pressure degrees

There are different degrees of low pressure:

A low pressure of less than 90/60 mmHg but greater than 60/40 mmHg is considered mild hypotension ;
A low pressure lower than 60/40 mmHg but higher than 50/33 mmHg is considered intermediate grade hypotension ;
A low pressure of less than 50/33 mmHg is considered severe hypotension .

Low blood pressure is often without clinical significance, especially if it is not accompanied by any symptoms; on the contrary, a low pressure of intermediate grade or, worse still, a low pressure of severe degree are generally the signal of a malfunction of the organism.

Types of hypotension

The medical community has drawn up a typological classification of hypotension, which is based on the causes and modalities of appearance of the decrease in blood pressure.

Among the types of hypotension that fall under this classification, they are noted for their notoriety and their spread: orthostatic hypotension and postprandial hypotension .

Also known as postural hypotension, orthostatic hypotension is the condition of low pressure that is established after the sudden transition from a sitting or lying position to a standing position.

Postprandial hypotension, on the other hand, is the condition of low blood pressure that occurs after meals.

Hypotension is the opposite of hypertension

Hypotension is the exact opposite of hypertension or high blood pressure .

Hypertension is the condition characterized by arterial pressure values at rest above 140/90 mmHg.

High blood pressure is a serious clinical circumstance, associated with a significant increase in cardiovascular risk .

Causes

For an individual, low blood pressure can be:

A constitutional, physiological condition, sometimes present without a precise and recognizable reason, and sometimes because of particular life choices, on all the regular practice of physical exercise.

A condition dependent on the presence of specific circumstances, including mainly some pathological conditions ( pathological hypotension ), certain pharmacological treatments ( drug hypotension ) and the state of pregnancy ( low blood pressure during pregnancy ).

In the first case, low blood pressure tends to be mild and lack an associated symptomatology; for doctors and experts, an arterial pressure with these characteristics is devoid of clinical significance and can even be considered positive for health ( benign hypotension ), since it protects from various cardiovascular diseases (eg stroke, myocardial infarction, etc.).

On the other hand, in the second case, low blood pressure is a condition of some clinical relevance, almost always combined with a symptomatic picture and worthy of the attention and eventually the care of a doctor.

Curiosity: what can lower blood pressure during the day?

During the day, various situations can temporarily lower blood pressure (which does not mean suffering from low blood pressure). Among these situations, we highlight:

Sleeping . The nocturnal sleep always coincides with a lowering of the arterial pressure, which rises again at the moment of awakening, until it reaches its peak at noon;
Having eaten recently . The digestion of recently ingested food draws blood to the stomach and intestines, removing it from the other organs of the body. The lower blood supply to these organs is a reason for a reduction in general blood pressure;
Moments of relaxation . Relaxation is associated with a decrease in blood pressure levels; on the contrary, stress always accompanies an increase in blood pressure.
Find yourself or go to particularly hot environments . High ambient temperature is a reason for reducing blood pressure.

Constitutional hypotension without recognizable causes

Although there is no definite evidence on the matter, experts believe that constitutional hypotension without apparently recognizable causes may depend on hereditary factors or a certain family predisposition to low blood pressure.

Low constitutional pressure and sport

Sportspeople - in particular endurance athletes (eg cyclists, marathon runners, etc.) - have lower arterial resting pressure than sedentary people, because, compared to the latter, they have a much more extensive network of capillaries ( network of capillaries that have developed after years of training).

Pathological hypotension

Pathological hypotension can depend on various diseases and medical conditions.

These diseases and medical conditions include:

Severe bleeding, prolonged dehydration due to vomiting and diarrhea, dehydration following extensive burns, dehydration induced by excessive sweating, Addison's disease, diabetes, anemia due to folate deficiency or vitamin B12, and episodes of anaphylactic shock. All these medical-pathological circumstances have in common the fact that they cause low pressure through the reduction of volume ( hypovolaemia );
Myocardial infarction, congestive heart failure, some forms of arrhythmia, bradycardia, valvulopathies and pulmonary embolism. Common to these pathological states is the fact that they cause hypotension by decreasing cardiac output ;
Sepsis, septicemia, septic shock syndrome, acidosis, severe brain trauma and severe spinal cord injuries. The common denominator of these medical-pathological conditions is the fact that they severely reduce the arterial pressure through the excessive vasodilation of the arterioles (from which a decrease in the peripheral resistances derives).

Drug hypotension

The list of drugs that can cause low blood pressure includes:

Calcium channel blockers, trinitrina (or nitroglycerin), angiotensin II receptor blockers (or sartans), alpha-blockers and anesthetics used for spinal anesthesia. These medicines cause hypotension through excessive vasodilation of the arterioles;
Diuretics. They can induce hypotension by reducing the volume;
Beta blockers. They can cause hypotension due to an abnormal reduction in cardiac output;
Narcotics, tricyclic antidepressants, the levidopa-carbidopa combination and some medicines for erectile dysfunction (including sildenafil or Viagra, vardenafil or Levitra, and tadalafil or Cialis) when used in combination with nitroglycerin.

Hypotension in pregnancy

Pregnancy is accompanied by a decrease in blood pressure, due to the important peripheral vasodilation induced by progesterone (a sex hormone essential for the correct development of fetal growth).

To investigate the functions of progesterone during pregnancy: Hormones and pregnancy

In the first 24 weeks of gestation, there is an average drop in systolic blood pressure of about 5-10 points and an average decrease in diastolic blood pressure of more than 10 points.

Main causes of orthostatic hypotension
pharmacological:	Diuretics, antihypertensives, tricyclic antidepressants, monoamine oxidase inhibitors (MAO inhibitors) and alpha-blockers.
pathological:	Addison's disease, diabetes, Shy-Drager syndrome, dehydration, multiple systemic atrophy, porphyria, pheochromocytoma, dysautonomia, anemia, anorexia nervosa and Ehlers-Danlos syndrome.
Other:	Prolonged immobility in bed and marijuana consumption.

Symptoms and complications

As stated, depending on the triggering causes, low blood pressure can be symptomatic or asymptomatic, in other words it may or may not be responsible for symptoms and signs.

When hypotension is symptomatic, the symptoms and signs to which it most commonly occurs are:

Dizziness, dizziness and confusion;
Blurred vision;
Sense of fainting that sometimes results in real fainting ( syncope );
Nausea and vomit;
Concentration problems;
Sense of instability;
Palpitations.

Complications

When low blood pressure is severe (for example due to serious pathological states), the organs of the individual concerned do not receive the amount of blood necessary for their proper functioning and maintenance.

This can lead to a state of shock .

Characterized by pallor, cold sweat, fast and shallow breathing, and weak and rapid pulse, the shock, in the absence of timely and adequate treatments, can have lethal consequences.

OTHER COMPLICATIONS

Fainting episodes to which an individual with symptomatic low blood pressure is subject may be responsible for injuries and trauma from falling .

It is not infrequent, in fact, that people suffering from hypotension fainting undergo limb fractures or brain traumas.

Why is low blood pressure causing symptoms?

Low blood pressure becomes symptomatic and takes on clinical significance, when the effects it produces on blood circulation are responsible for a cerebral suffering .

It is therefore based on the degree of cerebral suffering that the symptoms can be more or less intense: in fact, a mild cerebral suffering causes slight disorders, such as dizziness in getting up quickly from a lying position; on the contrary, severe brain suffering causes important manifestations, such as episodes of syncope (or fainting).

Speaking of syncope, this event is a real defense mechanism, which the organism implements in order to protect itself from the negative effects of an excessive pressure drop. In fact, when an individual faints, the resulting lying position causes the blood to encounter less difficulty in its path and more easily reach the heart and the brain.

For the same reason, while awaiting medical help, a person suffering from a cardiovascular collapse must be placed in the supine position, with the lower limbs raised (to facilitate venous return) and the hypertensive head (to avoid suffocation). If they are present, it is also useful to loosen the laces and belts.

Curiosity: why do people with low constitutional pressure do not faint?

When hypotension is a constitutional characteristic, the body of the person concerned has learned to effectively compensate for this situation, with an adjustment of the blood supply to the vital organs.

This adjustment is what avoids fainting episodes.

Diagnosis

Hypotension is easily diagnosed by simply measuring blood pressure, using a sphygmomanometer .

However, an accurate diagnosis of low blood pressure cannot be limited to the simple observation of reduced resting blood pressure levels, but must also focus on the search for the triggering causes and on the characteristics of the ongoing problem. This explains why physicians, when faced with a case of hypotension, subject the patient to a thorough physical examination and a precise medical history, and can even prescribe:

Blood tests, to study blood glucose levels (diabetes?), Cortisol levels (Addison's disease?), The number of red blood cells (anemia?), Etc .;
Urine tests, to search for possible infections;
An electrocardiogram, an echocardiogram and an exercise test, for the evaluation of heart health and the search for heart disease;
The pressure holter, to better understand what causes the drop in blood pressure during the day;
Radiological examinations, such as chest CT or chest X-ray, to further study heart health and observe the lungs;
The so-called passive orthostatic stimulation test, to understand if hypotension can depend on a malfunction of the nervous system.

Why look for the causes of low blood pressure?

Identifying the conditions that underlie hypotension is important, because it allows the most appropriate therapy planning.

Therapy

When low blood pressure lacks an associated symptomatology and is considered constitutional, it generally does not require specific treatments or treatments. As stated, in fact, such a circumstance does not represent a danger to the health of the person concerned.

The speech changes considerably when hypotension is symptomatic and depends on a specific cause: in such situations, in fact, low blood pressure requires specific therapy against the triggering factor. For example, if hypotension depends on a particular pharmacological intake, the treatment consists in interrupting this assumption.

Useful remedies against symptomatic constitutional low blood pressure

Sometimes, even constitutional low blood pressure can cause symptoms, almost always light, similar to disturbances.

In such situations, doctors advise to: increase water and salt intake (so drink a few more glasses of water and slightly increase the amount of salt in the diet), avoid excessive alcohol consumption, avoid caffeine (especially at evening and before bedtime), wear elastic compression stockings (as they favor venous return from the lower limbs to the heart), avoid the consumption of too abundant meals and, finally, pass slowly from the lying to the erect position.

It should be pointed out that the possibility of a symptomatology associated with constitutional hypotension is more frequent in the summer months - that is when it is warmer - as high temperature is a factor that accentuates and favors the condition of low pressure.

To learn more: Diet Against Low Pressure »