Goosebumps arise when tiny muscles around hair follicles contract, causing the hair to stand on end. Learn what triggers them and when they may be cause for concern.

Goosebumps, scientifically known as cutis anserina, are an involuntary response triggered by the contraction of arrector pili ...

Your arm hairs stand at attention when you’re cold or frightened, creating tiny bumps across your skin in a response that accomplishes absolutely nothing useful for modern humans. This vestigial ...