What causes goose bumps to appear on your skin

(Daily qudrat)Goose bumps cause due to an involuntary nervous system response called the pilomotor reflex This appears when hair follicles are stimulated by specific nerves in the skin, in the response to chills or thrills meaning cold temperature or strong emotional or psychological stimuli.
Here are some of the reasons of your goosebumps.
It’s chilly
Coldness activates the nerve from the sympathetic branch of the involuntary nervous system cause constriction of blood vessels in the skin, which conserves body heat. This nerve also triggers the pilomotor reflex and results in goose bumps.
You’re feverish

Brain area hypothalamus regulates your targeted body temperature. Fever is caused when the hypothalamus increases your body’s target temperature to an above-normal level. This stimulates sympathetic nerves to your skin. Hence, goose bumps can occur.
That was scary
Sympathetic nervous system stimulates your fight-or-fight response. This can be triggered in dangerous or scary situations and makes your hair stand up.
Riding emotional waves
Strong and intense emotions also trigger a wave of goose bumps. Almost any strong emotion can potentially stimulate the pilomotor reflex including love, joy, anger and sadness. It can also occur while recalling your old memories.
Faulty firing
It might be appeared due to faulty firing of the sympathetic nervous system. There is a disorder called pudendal neuropathy in which goosebumps appeared on the skin along with pelvic pain.