Loss Of Consciousness: A Symptom Not To Be Underestimated
Loss of consciousness or knowledge are equivalent expressions in medicine to indicate the same clinical picture. Both terms are valid since the loss of knowledge implies a detachment of consciousness from reality. That is, we lose the perception of the environment and of ourselves.
The underlying mechanism of this event, whatever the reason, is the lack of adequate cerebral irrigation. This means that for a few moments, not enough blood reaches the brain, causing a disconnect from the surrounding reality.
Within the loss of consciousness, an unpleasant situation is syncope, commonly known as fainting, in which the person reconnects with reality spontaneously. Spontaneous recovery is facilitated by the same fall that brings the body to a horizontal position, thereby increasing blood flow to the brain.
In small terms, a syncope is a loss of consciousness of cardiac origin. This is an episode that can occur with relative frequency. According to statistics, about 3% of emergency room visits are due to syncope. To better understand the causes of this phenomenon, which range from low-risk to more dangerous situations, we can divide them into cardiac and non-cardiac.
Non-cardiac causes of loss of consciousness
Vasovagal syncope
Let’s start with the most frequent cause. Vasovagal reflex syncope is an involuntary response of the nervous system to a certain stimulus. It causes immediate vasodilation, drop in blood pressure and redistribution of blood to the lower limbs. Sometimes it can be caused by a stressful situation, severe pain, dehydration, or an extreme outside temperature.
Change of position
Rapidly changing positions without giving the body time to activate compensatory mechanisms causes hypotension. This happens, for example, when we stand up from a lying position.
The arterial pressure is lowered and the blood, as it happens in vasovagal syncope, is distributed to the lower limbs, stopping to irrigate sufficiently and the brain.
Migraine
A very severe headache, such as a migraine, can be accompanied by a set of symptoms known as aura. Among these we find the temporary loss of consciousness.
Hypoglycemia
A decrease in blood glucose values can also cause loss of consciousness. This is a common situation in people with diabetes who are prone to blood sugar changes due to medication or diet.
Antihypertensives
Those suffering from arterial hypertension generally take drugs with different actions. One of the mechanisms of action of this group of drugs is fluid loss through increased urine and vasodilation. Both mechanisms can cause blood pressure to drop too low, causing fainting.
Stroke and loss of consciousness
It is the most serious of the non-cardiac causes and represents a risk to life. Stroke, or cerebrovascular accident, can be ischemic (blockage of the brain arteries) or hemorrhagic (rupture of a brain vessel).
Cardiac causes of loss of consciousness
Arrhythmia
A heart with arrhythmia beats irregularly and abnormally. These heart rhythm changes can cause insufficient blood supply to the brain for a short or prolonged period. As a result, a loss of consciousness can occur.
Diseases of the aorta
The aorta is our main artery and is responsible for distributing the blood pumped by the heart. If it doesn’t work well, it can decrease blood flow to other organs.
Since the brain is above the level of the heart, it needs good blood pressure to be irrigated. Diseases such as aortic dissection or aortic aneurysm have loss of consciousness as one of the first symptoms.
Heart myopathies
When the heart has muscular alterations, it is referred to as myocardiopathy. A frequent situation is the enlargement of the left ventricle, which is in charge of pumping blood to the aorta. In these cases, the same consequences as described for aortic diseases occur.
Valvulopathies
The cavities of the heart communicate with each other through valves; these force the blood to circulate in one direction only, without reflux. When the valves do not close properly or are too tight, the amount of blood reaching the brain is reduced.
What to do in case of loss of consciousness?
There are many factors that can lead to loss of consciousness and it is always good to give this symptom the right attention. It can be, in fact, a minor fainting and without consequences or a signal that announces a heart disease.
First you need to visit the doctor and undergo the necessary checks. Typically, however, tests will be done some time after the episode, when the patient has recovered.
If the fainting is sudden, without a clear explanation and without fast recovery, it will be the case to go to the emergency room or to the doctor to rule out the occurrence of a stroke or a serious heart problem.
