Fainting (syncope) is a short-term loss of consciousness, in which muscle tone decreases sharply, then – after a minute or two – the person returns to consciousness without resuscitation.
There are different types of syncope, and in each case, the prognosis is different. However, the essence of this condition is always that the brain does not receive enough blood, it stops working normally, and loss of consciousness occurs.
Three main types of fainting
1. Reflex ( neurotransmitter ) syncope occurs due to a malfunction of the nervous system and, as a result, vasodilation and a decrease in heart rate (bradycardia). Systemic arterial pressure drops, and as a result, the blood supply to the brain is disrupted. There are two types of reflex syncope:
Vasovagal ( neurocardiogenic ) syncope occurs when the autonomic nervous system that regulates blood pressure and heart rate is disrupted. This is the most common type of fainting, especially among athletes, young and generally healthy people. Usually , vasovagal syncope occurs with a person who is standing or sitting. In this case, there is often a pre-fainting state: dizziness, lightheadedness, flushing, pallor, nausea, vomiting, abdominal pain, excessive sweating. There is usually no cause for concern with vasovagal syncope. Such fainting can happen after a strong cough, sneezing, laughing, fright, severe pain, at the sight of blood, as well as while being in a crowded place, in a hot room, in the sun, after physical exertion, urination, defecation, etc.
Carotid sinus syncope that occurs when pressure is applied to the carotid sinus (the enlarged part of the common carotid artery). This, for example, can occur when the neck moves (in particular, when a man shaves and turns his head), and also if the shirt collar is too tight
2. Fainting due to orthostatic hypotension. Orthostatic hypotension is a decrease in blood pressure during a change in position from horizontal to vertical, that is, at the moment when a person stands up. It can occur for a variety of reasons:
from dehydration (including on the background of diabetes mellitus)
in Parkinson’s disease
after taking antiarrhythmic or antihypertensive drugs (especially in the elderly in the heat), antiemetics, antidepressants and antipsychotics
from drug and alcohol abuse
due to internal bleeding as a result of a violation of the integrity of internal organs after an injury or due to complications of various diseases
after prolonged standing, especially in crowded, stuffy places
3. Cardiogenic syncope is associated with a violation of the heart. It can occur even when a person is lying down. Usually there are no harbingers – a person abruptly loses consciousness. This type of fainting indicates a serious threat to life and health. It is more common in people with a family history of unexplained sudden death or early cardiovascular disease. The cause of fainting can be:
ischemia (lack of blood supply) due to a strong narrowing of the coronary vessels, as well as a tumor or thrombus that disrupts the patency of a large vessel;
structural changes (cardiac tamponade, aortic dissection, congenital anomaly of the coronary arteries, hypertrophic cardiomyopathy , etc.).
Sometimes fainting can be associated with hypoglycemia (too low blood glucose levels) in diabetes mellitus, panic or anxiety disorder, etc.
convulsive epileptic seizure can also look like a faint , but it lasts longer than a normal faint, and after it the person does not immediately come to his senses. Also, during an attack, the patient may bite his tongue, sometimes there is incontinence of feces or urine.
Loss of consciousness in some cases is caused by serious neurological disorders: stroke, transient ischemic attack, subclavian steal syndrome (deterioration of blood supply due to narrowing or blockage of the lumen of the subclavian artery), severe migraine.
Loss of consciousness after a traumatic brain injury also cannot be called fainting; in this situation, you should definitely consult a doctor to assess the severity of the damage.
In rare cases, loss of consciousness can be caused by narcolepsy, a disorder in which a person experiences daytime sleep attacks and cataplexy (sudden muscle relaxation).
When should you see a doctor if you faint?
If you faint, this is not always a reason to see a doctor. For example, if there was nothing like this before, if this is the first fainting in several years, then most likely you do not have any life-threatening diseases. However, there are “red flags” for the person themselves and for those who have witnessed fainting, indicating that medical attention should be sought:
fainting lasts more than 2 minutes;
fainting often recurs;
You fainted for the first time in your 40s;
You were injured during a faint;
you have diabetes;
You are pregnant;
you have had or have heart disease;
before you fainted, you felt chest pain, a strong or irregular heartbeat;
during fainting, urinary or fecal incontinence occurred;
if you have shortness of breath.
What will the doctor do?
The doctor must understand what is the cause of fainting and whether there is a threat to life and health. To do this, he will ask about the episode itself, about the medical history, about the illnesses of relatives (especially about early heart problems), conduct an examination and make an electrocardiogram. It is very important to tell the doctor about everything you felt before and after fainting, as additional symptoms can be very helpful in diagnosing. For example, chest pain in some cases indicates an acute coronary syndrome (myocardial infarction or unstable angina) or pulmonary embolism. A rapid heartbeat is often a sign of an arrhythmia. Shortness of breath may be a manifestation of heart failure or pulmonary embolism. Headache in some cases indicates vascular disorders and hemorrhages.
Often, the patient, among other things, is tested for fecal occult blood (this checks for bleeding in the gastrointestinal tract), a blood test determines if there is anemia, and a blood test for brain natriuretic peptide is also done (it can indicate problems with heart). The woman will most likely be given a pregnancy test. The doctor can see how much the pressure and pulse change with a change in body position.
If the doctor thinks that carotid sinus syncope is likely to have occurred, a carotid sinus massage will be required to confirm the diagnosis.
If a subarachnoid hemorrhage is suspected, a CT scan of the brain and a lumbar puncture may be needed.
If the doctor has a suggestion that the matter is in epilepsy, he will prescribe an electroencephalography.
If you suspect heart problems, your doctor may take you to the hospital for observation, send you for an ECG and echocardiography, Holter monitoring (24-hour ECG recording), an electrophysiological study of the heart, or coronary angiography. In difficult cases, an implantable (subcutaneous) loop ECG recorder can be installed for several months.
A high risk of severe consequences is indicated by:
structural changes in the heart
symptoms indicating heart failure (shortness of breath, weakness, fatigue, swelling, etc.)
low blood pressure (systolic – “upper” – below 90 mm Hg. Art.)
shortness of breath before or after syncope, or at the time of presentation
blood hematocrit less than 30%
advanced age and comorbidities
sudden death in the family due to heart problems
Treatment after fainting
Whether you need to undergo any treatment after fainting depends on the cause of its occurrence.
With reflex syncope, provoking factors should be avoided, since no treatment is required in this case. If you faint when your blood is drawn, let the nurse know about it – she will lay you on the couch before pricking your finger or giving you an injection. If you do not understand what exactly causes fainting, but the doctor said that there is no threat to health, you can keep a diary to identify provoking factors.
With anemia, it is necessary to find out its cause and correct it: the spectrum of conditions that led to anemia is very wide – from an unbalanced diet to a tumor.
With low blood pressure, it is recommended to avoid dehydration, do not eat large portions, drink caffeinated drinks. To prevent the pressure from dropping sharply, after you get up, you can resort to special maneuvers: cross your legs, tighten the muscles in the lower body, clench your fists or tighten the muscles of the hands.
If fainting is provoked by taking any medications, the doctor will cancel or replace the offending drug, change the dose or time of admission.
Some heart conditions will require surgery, including the insertion of a cardioverter defibrillator (a device that controls the rhythm of the heart). In other cases, conservative therapy, such as antiarrhythmic drugs, helps.
First aid for fainting
When you feel that you will soon faint (a pre-fainting state or, for example, causeless yawning), lie down so that your legs are higher. Or sit down with your head between your knees. This will allow more blood to flow to the brain. If you still lose consciousness, after you come to your senses, do not get up immediately. It is better to give yourself 10-15 minutes to recover.
If a person begins to lose consciousness in front of you, follow the same instructions: put him so that his legs are higher than his head, or plant him and lower his head between his knees. It is also better to unbutton the collar, loosen the belt. If a person does not come to his senses for a long time (more than 2 minutes), lay him on his side, monitor his breathing and pulse, and call an ambulance. The use of ammonia is not recommended: firstly, it is not clear whether it brings a person to consciousness faster, and secondly, it can be dangerous in some diseases, for example, in bronchial asthma.