I've experienced it a lot(needles). They actually don't hurt, but it's scary! When the put the needle in and started letting the anesthesia enter my bloodstream, it didn't
hurt, but I was in tears because of stress. It knocked me out quickly. I asked the nurses/doctors and mom "when am I going to fall asleep?" and the nurse saw me getting sleepy, and said: "You're already falling asleep." and just before I was about to answer, I was gone!
My mom puts on an emla patch before they use the needles since it numbs my arm and really helps me! I have to get blood testing every few months to check my iron levels(I have a deficiency). Once I was so scared that I held my breath for the whole duration they were taking my blood and I almost passed out!

I really wanted to know my blood group, so they took some extra blood(It's B- I think- it's the same as my mom.. yeah it's B-).
The "procedure" is just an endoscopy to check out what is happening in my bladder, kidneys, etc.
Why? Because I have ongoing infections and they(the doctors) can't find out what's going on. I've had testing done with urine samples but they come back inconclusive!
it's at the point were I will wet myself sometimes because I can't control my bladder anymore really.. Oh well, I've gotten used to the discomfort I feel every second of every day.