For me, it was more like....
Me: "I may get dizzy after getting my blood drawn. It happens every time."
Nurse: "Don't be silly. It's just a little blood. You'd be fine."
Me: "Fine, don't believe me."
*Blood Drawn*
Nurse: "Okay, you can go do the X-ray now."
Me (after walking away five steps later): "Um yeah, look how I have blood down my arm now. It didn't stop bleeding."
Nurse: "Ahhh!!! Sit down! Put your head down!"
*Head spins as some tremendous pressure was put on my arm to stop the bleeding.*
Another Nurse: "What happened?"
Nurse: "Some people are just afraid of blood, I guess."
Me:
+
Me in my head: "You moron. I already told you this would happen. People who are afraid of blood would not be able to raise a bloody arm into your face to tell you there's a problem."
Result - Me having a giant bruise on my arm instead of a red dot like other people.