# Why are drops of blood (for tests and the like) usually taken from the finger/hands? **URL:** \ **Category:** Factual Questions\ **Created:** [July 17, 2012, 1:18pm UTC](https://boards.straightdope.com/t/why-are-drops-of-blood-for-tests-and-the-like-usually-taken-from-the-finger-hands/628513 "2012-07-17T13:18:30Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![Bisected8](https://avatars.discourse-cdn.com/v4/letter/b/a4c791/32.png) [@Bisected8](https://boards.straightdope.com/u/Bisected8)\ **Post date:** [July 17, 2012, 1:18pm UTC](https://boards.straightdope.com/t/why-are-drops-of-blood-for-tests-and-the-like-usually-taken-from-the-finger-hands/628513/1 "2012-07-17T13:18:30Z")
Is this just a standardised way of doing it, or is there some advantage to pricking the finger? ---
**Author:** ![Keeve](https://avatars.discourse-cdn.com/v4/letter/k/f07891/32.png) [@Keeve](https://boards.straightdope.com/u/Keeve)\ **Post date:** [July 17, 2012, 2:06pm UTC](https://boards.straightdope.com/t/why-are-drops-of-blood-for-tests-and-the-like-usually-taken-from-the-finger-hands/628513/2 "2012-07-17T14:06:47Z")
Convenient and easy-to-reach? ---
**Author:** ![Smeghead](https://avatars.discourse-cdn.com/v4/letter/s/f1d935/32.png) [@Smeghead](https://boards.straightdope.com/u/Smeghead)\ **Post date:** [July 17, 2012, 2:42pm UTC](https://boards.straightdope.com/t/why-are-drops-of-blood-for-tests-and-the-like-usually-taken-from-the-finger-hands/628513/3 "2012-07-17T14:42:43Z")
Yep. Also the skin is relatively thin, with plenty of blood just below the surface, unlike, say, the belly, where my wife just got a shot and didn’t bleed at all. ---
**Author:** ![Shinna\_Minna\_Ma](https://avatars.discourse-cdn.com/v4/letter/s/f08c70/32.png) [@Shinna\_Minna\_Ma](https://boards.straightdope.com/u/Shinna_Minna_Ma)\ **Post date:** [July 17, 2012, 3:24pm UTC](https://boards.straightdope.com/t/why-are-drops-of-blood-for-tests-and-the-like-usually-taken-from-the-finger-hands/628513/4 "2012-07-17T15:24:33Z")
You may or may not already know this, but in the olden days when you went to the Red Cross to donate blood, they pricked the earlobe for the iron test, not the fingertip. ---
**Author:** ![Sicks\_Ate](https://avatars.discourse-cdn.com/v4/letter/s/258eb7/32.png) [@Sicks\_Ate](https://boards.straightdope.com/u/Sicks_Ate)\ **Post date:** [July 17, 2012, 3:34pm UTC](https://boards.straightdope.com/t/why-are-drops-of-blood-for-tests-and-the-like-usually-taken-from-the-finger-hands/628513/5 "2012-07-17T15:34:07Z")
"No, nurse, I said to _prick_ his _finger!"_ Never gets old. ---
**Author:** ![kenobi\_65](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kenobi_65/32/13178_2.png) [@kenobi\_65](https://boards.straightdope.com/u/kenobi_65)\ **Post date:** [July 17, 2012, 3:39pm UTC](https://boards.straightdope.com/t/why-are-drops-of-blood-for-tests-and-the-like-usually-taken-from-the-finger-hands/628513/6 "2012-07-17T15:39:56Z")
At least for testing blood sugar (for diabetics), testing blood from your fingertip is more accurate than when taken from other places (such as the arm or thigh), especially if your blood sugar is rapidly changing (such as after eating or exercising). > **[Diabetes and Blood Sugar Testing](https://www.webmd.com/diabetes/how-test-blood-glucose)** > > WebMD explains blood sugar testing and diabetes. ---
**Author:** ![Floater](https://avatars.discourse-cdn.com/v4/letter/f/dc4da7/32.png) [@Floater](https://boards.straightdope.com/u/Floater)\ **Post date:** [July 17, 2012, 3:47pm UTC](https://boards.straightdope.com/t/why-are-drops-of-blood-for-tests-and-the-like-usually-taken-from-the-finger-hands/628513/7 "2012-07-17T15:47:07Z")
> [@Keeve](#): > > Convenient and easy-to-reach? Except if you try to do it on the fingertip of the wrong hand of someone playing a string instrument. ---
**Author:** ![Hermitian](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hermitian/32/470_2.png) [@Hermitian](https://boards.straightdope.com/u/Hermitian)\ **Post date:** [July 17, 2012, 3:56pm UTC](https://boards.straightdope.com/t/why-are-drops-of-blood-for-tests-and-the-like-usually-taken-from-the-finger-hands/628513/8 "2012-07-17T15:56:08Z")
Don’t forget that there are lots of nerves there, so pricking a fingertip will make sure that it hurts more. Wait, you mean that is not the goal of medical care? ---
**Author:** ![Athena](https://avatars.discourse-cdn.com/v4/letter/a/35a633/32.png) [@Athena](https://boards.straightdope.com/u/Athena)\ **Post date:** [July 17, 2012, 4:02pm UTC](https://boards.straightdope.com/t/why-are-drops-of-blood-for-tests-and-the-like-usually-taken-from-the-finger-hands/628513/9 "2012-07-17T16:02:40Z")
To elaborate on what **kenobi 65** said - diabetics take blood from the fingers because fingertips have a higher concentration of actual blood. You _can_ test from other spots, but you end up with [interstitial fluid](http://en.wikipedia.org/wiki/Interstitial_fluid), not blood, and you don’t get as accurate of a reading.