Having just given blood yesterday, and given several times in the last 15 years (in New York and New Jersey), I can also state that in the US, at least in New York and New Jersey, general donations (as opposed to directed donations) also have the ''opt out'' barcode stickers which yam describes in the Canadian system.
Aside from the long questionnaire, your general feeling of well-being and whether you've had an illness within an x period of time, when you go to give blood they will also check your temperature, blood pressure, and hemoglobin levels. All must be within normal ranges, and your hemoglobin level cannot be below 12. And Chiisuta reminds me that they also check pulse rate, and anyone over about 100 will be turned away.
To test your hemoglobin, they will prick one of your fingers, and place a drop of blood into a little testing unit which will display your level after about a minute. If your hemoglobin reading is too low, you will not be permitted to donate.
I've been turned away because of this in the past, and it is a bit of a pain. Especially the time I went to give a directed donation for my brother's father-in-law who was going to have open heart surgery. This is, however, extremely common in women who are generally somewhat anemic part of every month. I have found that eating iron rich foods and taking a good supplement every day or every other day for at least a week prior to donating can prevent being turned away.*
If you take a supplement, NEVER exceed the recommended dosage. Iron is extremely bad for you in excessive quantities. Vitamin C helps it be absorbed, so wash it down with some orange juice if you are so inclined. Avoid eating anything with calcium in it when you take a supplement as calcium inhibits iron absorption. I also recommend taking the supplement with some food, as I find it always does a number on my digestion (which is why I don't normally take iron supplements). It also helps to massage your finger tips a bit before you are tested, and to generally get the blood flowing in your hands.
Some iron rich foods: meats, beans, fortified grains, green vegetables (especially okra), dried fruit, molasses, dark chocolate. Check the labels for the percent daily value of iron. Some things touted for high iron have less than you'd think; say a hand full of nuts compared to a molasses cookie. Also, a friend who is an RN once told me that garlic helps build heme. I don't know how proven this is, but garlic is certainly tasty with meats, beans, fortified grains, and green vegetables....
Some thoughts on what to do the day you donate and afterwards.
- Eat breakfast, eat lunch, eat dinner. Eat good, balanced meals and snacks all day. Try to eat something no more than an hour but no less than half an hour before you donate.
Drink fluids, and make sure that most of them aren’t caffeinated. Keep hydrated all day, before and after donating. This will help your donation go faster and you'll feel better afterwards because your total blood volume will be optimized, which means the percentage they remove will be less than if you were dehydrated. Also, your body will want to replace the lost blood volume, so help it out and make plenty of fluid available.
Try not to eat anything excessively fatty right after you donate blood. I don't know why cookies are always set out for donors. They invariably make me slightly nauseous as my system tries to digest the fat. An orange is a much better sugar hit for right after donation.
- Don’t push getting up and going back about your business. Relax, have some juice, and just sit there for 15 minutes. Make sure you feel normal before you run off. If you are light headed, queasy, or otherwise uncomfortable or weird feeling, don’t go anywhere. If you feel really uncomfortable, let an attendant know, and lie down. TRUST ME. I’ve had this happen before, and it’s much worse getting halfway out of the hospital, making a mess of the lobby and fainting in the bathroom, only to get taken to emergency and having to spend an hour w/an IV for a friend. This is one lesson that has led to many of the recommendations on this list.
- Take good care of yourself eating and drinking-wise for a few days as your body replaces the lost blood cells. You’ll feel all the better for it!
One last thought, please consider signing up as a potential bone marrow donor. Even if you are found as a match, you can decline to donate for whatever reason. But, if you are eligible to donate blood, and feel comfortable with the idea of potentially donating marrow, you can help be part of a cure for someone with no other options. When you register, they take a blood sample to generate your marrow profile for their database. As a bit of perspective, I signed up with the National Marrow Donor Program (www.marrow.org) over 10 years ago and have never been contacted as a match. Minority donors are particularly needed but finding a match for anyone is extremely difficult, much more so than matching a blood type, so please consider it.
* Oh, to the women out there, please don't donate during or right after your period. Wait at least a week while amending your diet to compensate.