Causes Of Fainting

Has the brightness of the world faded into blackness within a split second? If it hasn’t happened to you, you have certainly seen it happen to someone else. Alternatively called ‘syncope’, fainting is elucidated by a diminished flow of blood to the brain that causes a rapid loss of consciousness. The underlying cause behind fainting is what should arouse more concern than simply waking the victim from unconsciousness. Although they wake up minutes after collapsing, the faint is a strong indication of a serious medical abnormality. Hence it is imperative to identify the cause of collapse without delay or check the person’s previous health records. Fainting is a frequent phenomenon that occurs when the body is exposed to a non-conducive environment for long periods of time. One of the chief culprits of fainting culprit is the ‘vagus nerve’ that connects the digestive system to the brain. Under variable circumstances, it tends to drain too much blood from the brain and inevitably leads to fainting. Reasons for fainting range from lack of essential nutrients to dehydration. Scroll down for a more in-depth overview.

What Causes Fainting

Heart Rhythm Changes
Heart rhythm changes easily account for most of the “blackouts”. Potentially life-threatening, if the heart’s ability to pump adequate blood supply is compromised and electrical system disrupted, the blood pressure will gradually start plummeting.  Alternatively, abnormal heart rhythms cause rapid heartbeats (tachycardia). This shortens the time gap between heartbeats essential to fill vessels with blood, thus decreasing diffusion of blood to other body parts.

Sudden Cardiac Arrest
Syncope occurs among certain athletes and youngsters due to unusual thickening of heart muscle parts which subsequently obstructs blood from exiting the heart. Unexpected increases and drops in blood pressure provoke blood to be drained from the brain leading to a fainting spell. It is hence crucial to maintain a steady heart to avoid cardiac arrest and sudden death. Take a pulse to determine the cause. More than 150 beats per minutes points towards rapid heart rate and less than 50 beats per minutes points towards a very slow heart rate.

Dehydration
When the system lacks sufficient water in the bloodstream, blood pressure is lowered and the vagus overtly stimulated. Relentless exposure to the scorching hot sun, vomiting and diarrhoea trigger the vagus nerve to pull excess blood from other body tissues including the heart. This episode culminates in dizziness and fainting.

Alcohol And Drugs
It happens all the time. A man who downs seven pegs of whisky, can barely stand in a straight line and often passes out on his way to the restroom. Excess consumption of alcohol urges you to keep urinating to the saturation point of dehydration. Blood vessels dilate, blood pressure drops and the party animal conks off. Similarly, all kinds of dangerous drugs produce these side-effects, if not worse. Opiates lower blood pressure and slow down your breathing while stimulants raise your temperature and so on.

Vertebrobasilar System
An alternative set of arteries (vertebral arteries) provide the base of the brain with blood. Narrowing of the vertebrobasilar system could set off a temporary intermission in the blood supply to the midbrain or reticular activating system. The reticular activating system must be turned on to keep the body awake, while the brain requires constant blood flow to attain oxygen and glucose for the cells to sustain life. If they are switched off, syncope is inescapable. 

Shock
Precipitated by bleeding or even severe allergies and infections, a shock not only triggers fainting but often leads to death. The victim is initially struck by perplexity and eventually zones out into a swoon. 

Postural Hypotension
When a person impulsively stands upright from a slouchy lying down position or even sitting without giving the body time to maintain the body’s blood pressure and blood flow to the brain, fainting is underway. Loss of intravascular fluid (blood and water within the blood vessels) does indeed cause syncope. 

Pregnancy
During pregnancy, the inferior vena cava (the large vein that returns blood to the heart) compresses with several bodily changes. This invariably leads to rapidly rising levels of blood pumping through a pregnant woman’s body and then a fainting spell.