Fainting, also called syncope, is a sudden, and generally momentary, loss of consciousness, or blacking out caused by the Central Ischaemic Response, because of a lack of sufficient blood and oxygen in the brain. The first symptoms a person feels before fainting are dizziness; a dimming of vision, or brownout; tinnitus; and feeling hot. Moments later, the person’s vision turns black, and he or she drops to the floor (or slumps if seated in a chair). If the person is unable to slump from the position to a near horizontal position, he or she risks dying of the Suspension trauma effect.
Factors that influence fainting are taking in too little food and fluids, low blood pressure, hypoglycemia, growth spurts, physical exercise in excess of the energy reserve of the body, emotional distress, and lack of sleep. Even standing up too quickly or being in too hot a room can cause fainting. Recommended treatment is to allow the person to lie on the ground with his or her legs slightly elevated. As the dizziness and the momentary blindness passes, the person may experience visual disturbances in the form of small bright dots (phosphene). These will also pass within a few minutes. If fainting happens frequently, or if there is no obvious explanation, it is important to see a physician.
More serious causes of fainting include cardiac (heart-related) causes such as an abnormal heart rhythm (an arrhythmia), where the heart beats too slowly, too rapidly or too irregularly to pump enough blood to the brain. Some arrhythmias can be life-threatening. Other important cardio-vascular conditions that can be manifested by syncope include subclavian steal syndrome and aortic stenosis
Many different terms are often used to describe what is collectively known as dizziness. Common descriptions include words such as lightheaded, floating, whoozy, giddy, confused, helpless or fuzzy. Vertigo, Disequilibrium and Pre-syncope are the terms in use by most doctors. Dizziness is sometimes a symptom of a balance disorder
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