Fainting is a loss of consciousness that occurs suddenly due to a metabolic disorder in the brain. This slowing of metabolism is associated with a decrease in cerebral blood flow and has nothing to do with epilepsy. When providing first aid to the victim and, if necessary, medical care, one should distinguish a simple syncope from an epileptic fit.
Far from always fainting is a consequence of a serious illness that poses a threat to human life.
Fainting can be a consequence of a drop in blood pressure, if the human body could not quickly adapt to changes in blood flow. So, with some diseases accompanied by a heart rhythm disturbance, the heart does not always cope with the sharply increased load with a decrease in pressure and is not able to quickly increase the blood outflow. In this case, the person will experience malaise as the need for cells in oxygen increases. This kind of fainting is provoked by physical exertion and is called syncope of effort (stress). Its reason is that the vessels of the muscles, while remaining enlarged for some time after the termination of exercise, contain enough blood to remove the metabolic products from the muscles. At the same time, the pulse rate decreases and, accordingly, the volume of blood ejected by the heart at each contraction decreases. Thus, blood pressure is reduced, which is the cause of fainting.
Fainting can be triggered by a sharp decrease in the volume of circulating blood during bleeding or due to dehydration (with diarrhea, profuse sweating, profuse urination and some diseases).
The cause of syncope can be nerve impulses that act on the compensatory mechanisms and are the result of various pains or strong emotions - for example, fear of blood.
Fainting may occur during certain physiological or pathological processes in the body, such as coughing, swallowing, or urinating. The cause of fainting with coughing and urination may be a strain that causes a decrease in the volume of blood returning to the heart. In some diseases of the esophagus, syncope may occur if food is ingested.
Anemia, a decrease in the level of sugar or carbon dioxide in the blood, along with hyperventilation of the lungs, can also provoke fainting. Increased respiration may be caused by anxiety.
Rarely, mostly in old age, a microstroke can manifest as a syncope with a sharp decrease in blood flow in a separate area of the brain.
Before losing consciousness, a person most often feels an attack of faintness, he feels sick, a veil appears before his eyes, flies, rings in his ears. To the harbingers of fainting also include a sudden weakness, in some cases - a yawn, in patients the legs may wobble and a feeling of approaching fainting may appear. The characteristic symptoms of fainting are cold sweat, pale skin, some people may have a slight blush. After losing consciousness, the skin acquires an ash-gray hue, the pulse has a weak filling, the heart rate either increases, or falls, the muscle tone is low, the reflexes are absent or weak. Pupils during fainting expand, slowly react to light. Symptoms of fainting continue, on average 1-2 seconds. With prolonged fainting - more than five minutes - convulsions or involuntary urination may occur.
Treatment of syncope involves treatment of the underlying disease and relief of syncope as such. A person who has lost consciousness is important to ensure the supply of blood to the brain. The patient is put on his back, turning his head to one side, and lifting his legs, or sitting down, while lowering his head between his legs. On the face of the patient you can splash cold water, release him from tight clothes, in a stuffy room you should open the windows. To increase the tone of blood vessels and raise blood pressure level, drugs are used: caffeine, ammonia.