Why do doctors flick needles before they inject you with them?

Question

Unless they just do it on TV for 'coolness' or 'look like I know what I'm doing' factor, why do doctors do that?

Answer 1

To make sure the air bubbles are out.

Answer 2

To get the air out. They flick the syringe to make the air rise to the top, then depress the needle to expel the air, leaving only medicine in the syringe.

Answer 3

its to get any remaining air bubbles out, nurses do it too.  

Answer 4

to get the air bubbles out i guess!!!

Answer 5

To get the air bubbles out

Answer 6

To make sure no tiny air bubbles are sticking to the sides of the syringe, or trapped in there somewhere. after they flick it, they usualy squirt a small amount of the contents out to release the air that might have been trapped in there. An air bubble injected into your vein could mess a person up.

Answer 7

Yeah, Make sure there are no bubbles.

bubbles can cause stroke and other clots throughout the body.  

Answer 8

They don't flick the needle they flick the container under the needle.  This brings all the air to the top to be ejected out before putting the medication into your body.

Answer 9

To remove any air bubbles.

Answer 10

to make sure there are no air bubbles in there

Answer 11

like everyone else said, air bubbles

Answer 12

to scare you

Answer 13

There are bubbles in the syringe.

We (not just doctors) flick them to make them rise to the needle, then we expel the air from the needle (& sometimes a bit of whatever you're injecting squirts out!*)

I'd also flick a syringe to help mix a diluted/ mixed drug I'd just drawn up.

*It doesn't mean you're getting short changed though- all ampules are bigger than they need to be because some of the drug always gets left behind in the syringe/needle.

You'd need a fairly large amount of air in a vein to cause you a dangerous embolism, but it's unprofessional & bad practice to let any air into the bloodstream.

The getting the air out of the syringe is more to ensure that the dose going into the patient will be the full amount shown on the side of the syringe.

Answer 14

To get the air bubbles out.

Answer 15

my guess is to just test the needle, make sure it's not loose, and also to shake the injection one more time, to kind of "mix it." or maybe they already did it, and do it as a "verification" for you showing you that this is legit, and safe :) AND cool. but most importantly, to get air bubbles out i would assume.

Answer 16

To get Air Bubbles out of it...

Answer 17

To get the air bubbles out. It could really do some damage if they released air into your veins like that.