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Dr. Andrew Rynne

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What makes someone faint at the sight of someone elses blood ?

what makes someone faint at the sight of someone elses blood ? Could this be a sign of heart trouble ?
Tue, 28 Jun 2011
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  User's Response
it's 'vasovagal' shock resulting in inability of your 'baro-receptors' to maintain the desired B.P.
Rheumatologist Dr. Raheesh Ravindran's  Response
Dear Madam,Vasovagal syncope is the most common cause of fainting. Vasovagal syncope occurs when your body overreacts to triggers, such as the sight of blood or extreme emotional distress. The trigger results in vasovagal syncope — a brief loss of consciousness caused by a sudden drop in your heart rate and blood pressure, which reduces blood flow to your brain.Vasovagal syncope is usually harmless and requires no treatment.
Vasovagal syncope occurs when the part of your nervous system that regulates heart rate and blood pressure malfunctions in response to a trigger, such as the sight of blood. Your heart rate slows, and the blood vessels in your legs widen. This allows blood to pool in your legs, which lowers your blood pressure. This drop in blood pressure and slowed heart rate quickly diminish blood flow to your brain, and you faint.
The cardiac system may not be at fault.
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  User's Response
hiroshi's  Response
It's called a 'vagal response'! It happens with stress, and pain too! There's a big nerve in your body, and when it's stimulated (by fore mentioned things) it puts the break on your nervous system (to keep you from getting too rilled up) but it goes into overdrive and tells your heart to slow down and your blood pressure to go down. Usually people will pass out, and once they're recumbent, they're OK. Nothing wrong with the heart, just an active vagus nerve. (usually!!!)
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