system
Given the following post, respond as if you're commenting on Reddit:
human
Why is the newborn heel prick test is done on the heel?

Wondering why the heel spesifically.
gpt
It's for convenience. The heel has blood vessels close enough to the skin surface, you can poke a big enough hole to get sufficient blood before it clots, you can easily bandage the site afterward, and it's relatively easy to hold the foot still while you do the collection. And the baby isn't going to disturb the band-aid by trying to walk around right afterward.