Im a blood donor. I have been donating for about 2 years now. Both the first and the last time i went, i threw up.
Now the cardiovascular system and the digestion system arent heavily related as far as im aware.
So how come the bloodloss causes naseau and vomiting?
In: 3
Drawing blood results in a drop in blood pressure: since there’s less blood in your veins it doesn’t “push” as hard. Think of trying to squeeze a balloon, then letting out a bit of air and squeezing again. Easier the second time, right?
This drop in blood pressure can result in fainting—called a Vasovagal Syncope. But before you faint, you might experience several other symptoms, including dizziness and nausea. So vomiting from blood donation is you almost experience a Vasovagal Syncope, but not quite getting all the way there. Vomiting can actually help prevent fainting, because it causes a temporary rise in blood pressure.
Another cause of Vasovagal Syncope for some people is seeing blood, which is obviously is likely to happen while donating.
The best way to prevent vomiting and fainting is to stay well hydrated before and after your donation. Unfortunately this isn’t a guarantee fix and many people experience adverse reactions regardless.
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