What causes goosebumps on the skin?
Goosebumps appear when the arrector pili muscles contract, pulling the hairs into an upright position.
On areas of the body that do not have much hair or that only have light hair, a person might notice only the erect hair follicle and not the hair itself.
Erect hair follicles look swollen and slightly bigger than usual. This enables them to hold the hair upright, and it also causes goosebumps.
A number of specific factors can give rise to goosebumps. These include: