What Causes Goosebumps?

Goosebumps are an evolutionary throwback that helped humans thousands of years ago, but today, not so much. In the 21st Century, they seem to serve a limited purpose other than as an entertaining party trick when some folks produce a cascade of the bumps on demand.

That pebbled surface reminiscent of the plucked skin of a dead goose (hence the name goosebumps) results from a process called piloerection. Tiny embedded skin muscles — piloerector muscles — are attached to individual hair follicles. When the piloerector contract, they cause a temporary rising of the hairs on the skin's surfaces.

When humans were hairy, this call to attention of skin hair created another layer of insulation to keep us warm. The "fluffed up" appearance also made us look larger and more threatening to ward off predator attacks. Think porcupine. This explains why the sympathetic nervous system — an involuntary mechanism tied to the fight or flight response — controls goosebumps.

Though cold and fear are the two most common triggers for the goosebumps, many brain regions connect to the sympathetic nervous system, including areas linked to motivation, arousal, and emotion. So other stimuli, especially those causing intense emotional experiences and an adrenaline rush, may result in a cascade of goosebumps and include:

Also: drugs. Two sisters who experienced goosebumps after taking milnacipran hydrochloride, (a medication for fibromyalgia), were described in a study. Drugs mimicking chemicals in the body that cause goosebumps may also trigger the phenomenon. For example, methamphetamine, which creates an adrenaline-like rush, may cause goosebumps.

Music and goosebumps

Music is loaded with variation. The sound can suddenly crescendo, quiet, or speed to a frenzy. Drums can boom. This abrupt change in sound and tempo comes as a "surprise" to your emotional brain and is perceived as a threat, which triggers the fight-or-flight response and raises goosebumps.

To your emotional brain, there's no such thing as a pleasant surprise, said Michell Colver, an instructor of special topics at Utah State University, the lead investigator in a study that examined the relationship between goosebumps and music that went viral.

It's not until seconds after the emotional brain interprets a screeching violin as a danger that the thinking brain kicks in with a cognitive take of the situation, and realizes the high notes are music, and closes down the emotional brain so the goosebumps fade.

Are goosebumps witchcraft?

Scientists identified and surveyed 32 people who claimed and described voluntary control of piloerection. Oddly, 80% used the same process to create the goosebumps, first describing building tension in the back of their head, neck, or ear, causing a local eruption that spread down the neck, back, or arms. It was characterized as effortless in the study published in PeerJ.

From a physiological perspective, controlling goosebumps on command should be impossible, however. The tiny muscles that contract and form bumps are smooth muscle, not skeletal muscle (that you can voluntarily contract), and they don't have a conscious connection to the brain.

Many scientists believe that other undiscovered cells or pathways must be involved in generating goosebumps.

The next hair loss therapy

Recently, another cell has been discovered as a vital part of the goosebump loop. In addition to the muscle, follicular, and nerve cells, activation of a follicular stem cell was found to be necessary, at least in mice. Without the involvement of the stem cell — a cell with the ability to develop into a variety of cells — goosebumps won't happen, the scientists demonstrated.

The study led to the realization that goosebumps not only provide temporary cold relief via hairs standing on end, but follicular stem cell activation triggers new hair growth providing long term warmth.

Though hair follicles are usually decreased in those with hair loss, finding a way to reactivate the sympathetic nerves in hair follicles may provide a way to increase hair growth.

Red flags for health issues

Though rare, goosebumps can be a sign of problems within the sympathetic nervous system, like a seizure disorder, most commonly temporal lobe epilepsy. They also happen during the withdrawal of certain drugs like opioids and heroin, research shows.

Goosebumps have been with us since prehistoric times for warmth, and they'll be with us when we die. The postmortem changes in muscle cells that cause rigor mortis, the build-up of lactic acid and stiffening, happen to activate the piloerector muscles, too.

So you'll be adorned with goosebumps, at least for several hours, on your way out.