Fainting blood donor ?

Nurses General Nursing


Can some-one explain to me why I am prone to fainting when I give blood? I have no history of fainting, so I'm very puzzled about this.

The first time I gave blood, I made it until the end of my donation, before I passed out. The second time,( which was monday) I passed right after the tube was inserted , and wasn't able to donate. Did the pain of the insertion cause me to faint?

I have never in my life had any other experience with fainting. It was weird for sure..... one minute, I'm sitting up fine, the next minute I was asleep and dreaming that I was going on vacation! :chuckle

Has anyone else had this happen to them?

sanakruz, ADN

735 Posts

I'll bet $10 you are holding your breath

sanakruz, ADN

735 Posts

And i dont mean for a reply, I mean you forgot to breath!

I would always tell folks "breath now" as i was drawing blood, (which I havent done in 14 years), but you would be surprised how many folks hold their breath in anticipation of something unpleasant. :)


135 Posts

Could anxiety be a component? Were you well hydrated?

I know that some bood banks wont let you donate after a couple of fainting episodes.

If you are going to try again, eat a meal beforehand, be well hydrated, some people advise not to donate whilst menstruating, make sure you are well. But take advice from the staff as to whether it's a good idea to try again or not. jax

sanakruz, ADN

735 Posts

I dont think enough of us respire fully at any given time, never mind when anxious among strangers.


366 Posts

Vagal response?

Specializes in CCU (Coronary Care); Clinical Research.

We just had a patient this week who's iv became disconnected so when the patient woke up, there was blood all over the bed. He vagaled himself right into 20 seconds of asystole. atropine brought him back to junctional and he had to be paced back into SR. Pt stated he has always gotten "faint" at the sight of blood. Yikes.

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dianah, ASN

9 Articles; 3,992 Posts

Specializes in RETIRED Cath Lab/Cardiology/Radiology.

Maybe donating blood bothers you more than you think. ;)

I was called stat to one of the X-ray rooms once to help with a man who had gone vagal. I was able to slip an IV in and we gave him atropine and fluids and he got better. Why was he there in the first place?? He was scheduled for a wrist arthrogram. He became vagal as the technologist was setting up the syringe and needle for the Radiologist. No one ever came near him with the needle, but he still responded that way.

One of the technologists I work with ALWAYS faints when blood is drawn in the lab. She used to come to us Radiology nurses for her blood draws, saying she felt more comfortable with a familiar face and manner around. We always had her lie down (so she wouldn't FALL down), and then just used the ol' vocal anesthesia, some humor, etc., while drawing the blood. She never fainted on us, so I guess we did something right!

OK, back on track: I agree w/ other posters: eat a good meal, hydrate thyself, warn the crew . . . I don't recommend you watch them stick the needle in, or for that matter, even look at the site or the bag, etc --- turn completely away until they have the bandage on your arm at the END. Use some imagery or something while you wait for that bag to fill -- read a book, etc.

Good luck! -- D

Mimi2RN, ASN, RN

1,142 Posts

Specializes in NICU.

My 6' 2'', 195lb son passed out cold after he donated the last time. They said he seized, but I'm not sure about that. Anyway, they told him never to donate again!

Specializes in Med/Surg, Ortho.

My son can watch brain surgery on tv, see other peoples blood, but when it comes to his,, even a finger cut that bleeds,, someone better get a chair cause hes goin down.

Believe it or not he now sells plasma to make extra money while in school. Go figure.

road runner2003

147 Posts

Fainted the first time I donated. After that the nurse told me next time I donate make sure to drink plenty of fluids throughout the day - course carbonated drinks don't count and eat a decent size meal within at least 4hrs of donation.

Specializes in ED staff.

When you donate blood you are of course decreasing the amount of blood you have in your body. Your body has to make adjustments for the decrease in circulating volume. Combine that with a little vagalness, and perhaps getting up too soon and there you have it. If you are fainting when you get stuck that's a vasovagal response. You remember from anatomy that the vagal nerve is a cranail nerve and if stimulated it causes a decrease in the heart rate, decrease HR means decrease in the amount of blodd getting to your brain. Not enough blood in the brain, you pass out. Some people even get a little twitchy when they pass out with a vaso-vagal episode. The good thing about a vagal episode is that once you get down on the ground you get the blood flow back to your brain and you wake up quickly. Can be very scary for those watching this happen to you.

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