Low blood pressure or hypotension is a problem that affects many people, especially in the summer. A feeling of weakness, mixed with dizziness, confusion, blurred vision and sometimes even loss of consciousness, which prevents you from carrying out any activity. But what exactly is low blood pressure and what are the symptoms, causes, optimal values and best remedies to combat it?
What is low blood pressure or hypotension
Low blood pressure, also known as hypotension, occurs when systolic blood pressure is lower than what is considered normal. In general, values below 90/60 mmHg of systolic blood pressure are considered low, even if the reference values can vary slightly also according to individual characteristics. This condition is quite common in the summer, since the heat, together with the humidity, favors the dilation of the blood vessels, reducing the peripheral resistance which, together with the force exerted by the heart to introduce the blood, characterizes the blood pressure.
But what is blood pressure? It is the measure of the force exerted by blood on artery walls as the heart pumps blood through the body. It is usually expressed in two numbers: systolic blood pressure (the top number on the blood pressure monitor) and diastolic blood pressure (the bottom number). Systolic pressure represents the pressure in the arteries when the heart contracts and pumps blood, while diastolic pressure represents the pressure when the heart relaxes between beats.
In summary:
- Systolic or “maximum” blood pressure: The blood pressure when the heart is contracting.
- Diastolic or “trough” blood pressure: The blood pressure when the heart is in the relaxation phase.
Blood pressure can vary throughout the day due to various factors such as physical activity, stress, posture and age. However, if your blood pressure is consistently low or high it can be indicative of a health problem.
Types of hypotension
There are several types of low blood pressure or hypotension, including:
- Orthostatic.
- Postprandiale.
- Neuromediata.
Orthostatic hypotension
Also known as postural hypotension, it is the most common form of low blood pressure and occurs when blood pressure drops significantly if a person stands or changes from sitting to standing. This type of low blood pressure can cause symptoms such as dizziness, fainting, or feeling weak.
This is because as you move from sitting or lying down to standing, your body must adjust quickly to maintain adequate blood pressure and ensure adequate blood flow to the brain and other parts of the body.
The causes of orthostatic hypotension can be different including dehydration, the use of certain medications, circulatory system or heart disorders, sitting or lying down for a long time without moving.
Postprandial hypotension
Postprandial hypotension occurs from a decrease in blood pressure after eating. It is a fairly common phenomenon and can occur in people with both normal blood pressure and already low blood pressure.
During digestion, in fact, the blood flow is channeled towards the digestive tract to help the absorption of nutrients that arrive from food. This can cause a temporary reduction in blood flow to other parts of the body, including the brain, which can lead to a decrease in blood pressure.
When this happens you may experience symptoms such as dizziness, fainting, weakness, confusion or blurred vision after eating. However, these are often transient symptoms that tend to resolve spontaneously.
Neuromediated hypotension
Also known as neural-mediated orthostatic hypotension syndrome, it is a specific form of postural hypotension that occurs due to an abnormality in the regulation of the autonomic nervous system.
The autonomic nervous system is involved in the control of involuntary functions of the body, including the regulation of blood pressure. Normally, when you stand up or change positions from sitting to standing, the autonomic nervous system regulates blood pressure to ensure adequate blood flow to the brain and other parts of the body.
In the case of neuromediated hypotension, the autonomic nervous system malfunctions, causing symptoms such as dizziness, fainting, weakness, and blurred vision.
The causes are not yet fully known, but may include genetic abnormalities, nerve damage, infections, or autoimmune disorders involving the autonomic nervous system.
Severe shock hypotension
This type is one of the most serious forms. In case of shock, in fact, blood pressure decreases considerably, so much so that the person concerned is in serious danger of life. There are several types of shocks:
- Hypovolaemic, usually triggered by severe internal or external bleeding, deep burns, severe dysentery, kidney disease, overuse of diuretic drugs, and other similar factors.
- Cardiogenic, a type of shock associated with causes such as heart attack, pulmonary embolism, or severe arrhythmia.
- Vasodilator, a shock associated with reactions to certain types of drugs, liver failure, poisoning, severe allergic reactions, or extensive head injury.
Low blood pressure: symptoms and warnings
It is a condition that can manifest itself through a series of symptoms and warning signs that indicate low blood pressure in the body. Some of the more common symptoms are:
- Feeling faint or dizzy. It is one of the most common signs of hypotension and manifests itself as a feeling of shakiness or dizziness.
- Weakness or fatigue.
- Blurred vision.
- Mental confusion or difficulty concentrating.
- Pallor. Due to decreased peripheral blood flow, the skin may appear pale or feel cooler to the touch.
- Excessive sweating, especially in the hands or on the forehead.
- Fast heart rate as the body tries to compensate for low blood pressure by increasing the heart rate.
- Feeling of cold in the extremities.
However, it is not certain that all hypotensive people show obvious symptoms. In fact, some people may have naturally low blood pressure without experiencing particular discomfort.
On the other hand, however, if hypotension occurs suddenly, even a loss of consciousness can occur. Sudden pressure drops, in fact, cause a reduced blood flow to the brain with the risk of fainting and falling to the ground. In this case, great care must be taken with the elderly to avoid the danger of fractures.
Fonte: OMS/ISH
Low blood pressure values
In general, a situation is considered normal in which the systolic pressure values (the maximum) do not exceed 130 mmHg and the diastolic pressure values (the minimum) 85 mmHg. 120/80 mmHg are the optimal values. Hypotension occurs when these values are less than 90 mmHg for systolic (maximum) and equal to or less than 60 mmHg for diastolic (minimum).
So values 110-100/70-60 can be considered within the norm even if slightly lower than the reference standard.
Classification is suggested by WHO/ISH, based on blood pressure levels in adults 18 years of age and older.
There are different degrees of low blood pressure:
- If less than 90/80 mmHg but greater than 60/50 mmHg, it is considered mild hypotension.
- If it is lower than 60/40 mmHg but higher than 50/33 mmHg, we speak of intermediate degree hypotension.
- If lower than 50/33 mmHg it is evaluated as severe hypotension.
Mild low blood pressure is not worrying, especially if there are no associated symptoms. Instead, an intermediate or severe degree of pressure is the sign of a malfunction of the organism, which must be investigated at a clinical level.
Low minimum (diastolic) blood pressure
A low minimum blood pressure can be considered when the diastolic blood pressure is constantly below 60 mmHg, i.e. the pressure level that marks the boundary between the state of normal blood pressure and the state of hypotension.
In other words, low trough blood pressure is defined as a condition in which the resting diastolic blood pressure is less than 60 mmHg.
As a rule, the minimum low pressure falls within a context of hypotension, therefore in a state in which even the systolic pressure (the maximum) is constantly lower than normal (therefore at 90 mmHg).
Low maximum (systolic) blood pressure
Low maximum blood pressure, known as systolic blood pressure, if below 90 mmHg can be considered low. The optimum is 120 mmHg. However, it is important to evaluate blood pressure in the overall context of a person, as reference values can vary depending on many factors, such as age, gender and general health.
Low blood pressure: when to worry? What to do?
In the case of non-occasional and continuous hypotension it can be worrying if significant symptoms occur or if the pressure is so low that it interferes with normal daily activities.
Symptoms that require medical attention and clinical investigation include:
- Frequent dizziness or light-headedness.
- Fainting or loss of consciousness.
- Severe weakness or fatigue.
- Wheezing and difficulty breathing or chest pain.
- Changes in vision or problems with balance.
In these cases it is advisable to consult a doctor for an adequate evaluation and, if necessary, the execution of any diagnostic tests to determine the cause of the low blood pressure and provide the most appropriate indications and treatment.
In the meantime, there are some steps you can take to…
