Actually it started because I was hospitalised when I was in elementary school. Before that I don't have it. I think it was because of a doctor who tried to insert the needle and failed. She tried to insert it about three times and when she managed to get it in, the entire bed was already full of blood. I still remember that.
A small bottle or test tube of blood won't do much damage. But I never go for blood donations. The sight of that packet of blood is too much for me to handle. Even when drawing blood from me, I don't look at it. But instead of seeing the blood itself, I think Im more fearful about seeing people bleed. Especially those that drip. So if someone cut themselves, please never let me look at it. I'll go crazy.