Would they know that before taking the blood and sending it to be analysed?

Yes. It literally takes a prick of the finger and a few minutes. It's supposed to be standard procedure before being allowed to donate.

The people who draw blood when you're giving a donation are not your doctor. They had no way of knowing what conditions you have before hand unless you tell them. They are not at fault here.

Except they're supposed to check iron before they even start any other prep, because if you are anemic or low in iron for any other reason, the blood is completely useless. It's a medical procedure that has guidelines they're supposed to follow, and they failed to do so. OP could have sustained a serious injury from them not adhering to protocol. They are at fault for their mistake.

That's never happened when I've donated blood. They only had me fill out a form and asked me a few questions. Maybe they just don't care when it's military donating to other military.

Or OP passed out from low volume status which is not an uncommon side effect of blood donation, even in totally healthy individuals.

Actually, any blood donation place worth beans tests your iron levels before donation (it only takes a few seconds and a small stick on your finger). So yeah it is their fault. If they'd tested OP for iron and it was that low they shouldn't have taken their blood in the first place

I believe OP meant that due to the reduced oxygen carrying capacity of her blood after the donation she had symptoms comparable to anemia, not that she had a pre-existing medical condition.

They check your blood iron levels to make sure you are able to donate. Therefore, they would in fact know if her iron levels were borderline.

You've never gotten that pinprick where they take a drop of your blood and put it into some liquid? The Red Cross does it. That's supposed to test for anemia. There's a minimum iron level you need to be able to donate.

They're supposed to check if donators are in the correct margins for iron (among other values) before starting. If not, they are supposed to turn them away, because they can't take use blood because it's effectively useless. The people doing the blood drive are 100% at fault for failing to follow procedure.

OP could have iron that's in the right margins and still have passed out from donating.

When you are in the right margins but it's close, they're still supposed to tell you. They also shouldn't be doing it in a non-sectioned off area because it involves people's medical information.

I always take someone with me when I give because blood donation makes me woozy.

And how exactly would STRANGERS at a blood drive KNOW her iron levels???

BECAUSE they test your iron levels before taking any donations! I've donated many many times and this is one of the first things they do. Quick stab, get a sample on a slide and stick it in a machine, 15 seconds later BOOM! Iron levels. It even has to be higher than just enough to be healthy because donating lowers the iron levels. OP could have passed out from just the blood loss itself, which can happen with no relation to iron levels

Would you have rather they immediately started giving you mouth-to-mouth? Yeah, right?

How could they warn YOU that YOU are borderline anemic? That's ridiculous!

At least now you know you'll be less prone to a vampire attack. Everybody knows they tend to seek blood high in iron.

Didn't they give you a cup of tea and a biscuit afterwards?

I had my blood drawn by my doctors for a blood test, it was 5 vials. I didn't pass out but I lost my hearing, could barely keep my eyes open or sit up straight. It came back I was completely healthy

Vaso-vagal syncope

For those of you wondering, most blood donations check your iron levels, and have you fill out some sort of questionnaire to make sure that you are fit for a donation. These tests can't register if you're ill, but they can accurately tell if you have anemia, or an iron deficiency, and help you determine if you have any sort of sickness. I myself have been to blood donations. You should go talk to your doctor about your anemia, good luck OP.

Walgreens at its finest!