Why do human blood types have anti-gens against each other?

Could it have something to do with pregnancy?

Antigens are just natural components of cell walls. Some blood cell antigens are sugar molecules, others are proteins. They aren’t there in order to trigger an immune response; they have other functions in the cell membrane. We call these particular molecules antigens because they’re the molecules the immune system “reads” when trying to determine whether a cell is foreign to that body. This is how it recognizes bacteria and knows to attack it.

Antibodies to the major ABO blood group antigens (no hyphen) are usually acquired by exposure to various plant proteins in the diet during childhood. So if you’re type A, you’ll develop anti-B antibodies & vice-versa, even without ever receiving a blood transfusion. The immune system prevents antibodies from forming against native antigens present on your cell surfaces.

I’m asking because near me there was a call for A negative, which I am, and I am trying to get to the bottom of this issue.

The last time I gave blood I started passing out, and they hit me with the smelling salts. Rather unpleasant.

I want to help, and I am wondering if anyone knows any of the adverse affects of blood donation?

If I gave today, I would then have to go and stand in the freezing cold to learn welding afterward.

I have a tendency to hyperventilate, if my physical condition taps my anxiety.

Should I avoid this donation unless I have ample recuperation time?

I don’t mean to hijack my own thread, but it is a pressing issue, someone needs blood like mine, and I feel like that is somewhat of a moral demand on me.

Donating blood is also something I would not like to be too scared to do when I have the desire to help people. The bottom line is that as long as I am not jeopardizing my own health, I am ready to donate, annually, at least.

Blood groups are actually by-products of other systems within the body. For example people with type AB blood are much less susesptable to cholera than people with type O group. In regions where cholera is more prevelant so is AB type blood. There is some benefit to having type O but I can’t remember what it is off the to pof my head. The fact that these surface antigens make blood donation more compliacted is just part of the fun of evolution.

@Ltryptophan Given that you started passing out the last time you gave blood, I’d highly recommend not giving blood when you have other things to do that same day that are going to require your energy. Instead, try to schedule it on a day when you will be able to relax and recuperate afterwards.

@Seaofclouds I agree. I just called the donation business. They said maybe I should do it when I have enough time to rest.

Does anyone know what the best blood recuperating foods or fluids are? I know sugary starchy stuff, brings your strength and energy back, but are there any specific things that will help someone like me who needs a little extra kick to come out of the drop. This calls for a new thread, which I am opening, keep a lookout.

Water is good because it doesn’t have any diuretics in it and can help with your blood volume. Sugary/starch is good for a quick energy pick up while your body responds to the blood loss. Time is the only thing that will get your actual blood counts back up.