Anyone who has ever had “the chills” can immediately recognize the signs, from the goosebump skin to the sudden, uncontrollable shuddering. The symptoms evaporate just as fast as they appear, leaving you to go on with your day as if nothing ever happened.
So what’s the deal with this phenomenon and why does it happen in the first place? Below is a breakdown of everything you never knew you wanted to understand about those shivers:
Here’s what happens to your body on the chills.
There are basically two types of “chills” that cause a physiological response: the shivers you get from a physical stimulus (for example, your body’s reaction to feeling cold) and those that come from an emotional stimulus (like seeing a happy ending to a story). How those chills appear on your body depends on which trigger is occurring, according to Hadley King, a board-certified dermatologist based in New York.
The physical triggers of the chills ― the reaction you have when you get caught in a cool gust of wind ― are more obvious. “Scientists theorize that it is probably an evolutionary leftover from our ancestors when we were covered with thicker hair. When we got cold, the hairs would stand up and trap a layer of air close to the skin, creating a layer of insulation,” King said.
The physicality behind emotional chills is a little less clear, according to King. It may come down to the neurotransmitter dopamine. A certain emotional stimulus triggers the brain, releasing the chemicals, and the body responds in kind. This leads to “transient paresthesia” ― AKA skin tingling ― and goosebumps. And some emotional triggers create a stronger response than others.
“When we look at research [on the chills], outside of the evolutionary response to warm ourselves, it’s music that seems to trigger it, as well as moving experiences and even movies,” said Kevin Gilliland, a Dallas-based clinical psychologist.
Frightening experiences ― like when you’re about to give a big presentation or you feel your safety is threatened ― are another type of emotional trigger. King said some scientists believe the chills can pop up here thanks to your fight-or-flight response. The release of adrenaline can induce the shivers or prompt goosebumps to form. This is a primal reaction, Gilliland added.
“You’ve likely seen dogs with their fur standing up on their back when they’re frightened,” Gilliland said. “It’s a natural response to a mixture of danger and fear and vulnerability.”
Some people are more prone to emotional chills than others.
There is some scientific evidence that your personality can affect how often you get the chills, Gilliland said, though more research needs to be conducted before any definitive conclusions can be made. He cited one 2007 paper published in the journal Motivation and Emotion that found “openness to experience” ― so someone who is game to try new foods, adventures and different ideas ― was a marker of getting the chills more frequently.
“Anything for humans that is a subjective experience — like pain, for instance — is hard to study,” Gilliland said. “But that’s what I love about it. This is one of the places where we see the bridge between the mind and the body.”
Matthew Sachs, a researcher at the University of Southern California, conducted a 2017 study that indicated those who experience a strong emotional response to music and then get chills may do so because of a structural difference in the brain.
Gilliland added that those who are “very rigid and structured,” as well as “less curious and imaginative,” and anyone “blocked by trauma, depression, anxiety and mental struggles,” likely won’t experience this dopamine rush and the subsequent chills as frequently.
“When we’re emotionally blocked, our hearts and minds are a little more closed down, or just trying to get by,” he said. “When that happens, our bodies go along for the ride.” So perhaps another reason to focus on rehabbing your mental health this year and finding a healthy balance: It just might give you the chills.
And what about the chills that aren’t prompted by a trigger?
As for the shivers and muscular jerks that come seemingly out of nowhere with physical or emotional prompt, this may be something called myoclonus. This is when the body has involuntary muscle jerking and spasming and there’s no determined cause.
Myoclonus is not the same thing as the chills, but it may be confused for it ― especially essential myoclonus, which is a subtype of the condition. That “occurs in the absence of epilepsy or other apparent abnormalities in the brain or nerves,” according to the National Institutes of Health, and can happen at random. It’s the same kind of “sleep start” jerk that your body may experience just before falling asleep.
In addition to myoclonus, there are myriad conditions (like thyroid issues) that may contribute to your body’s inability to regulate its temperature, resulting in a physical triggering of the chills. If you experience the chills frequently without any specific reasoning, you may want to chat with your doctor.
The more you know, right?
Clarification: Language in this story has been amended to clarify Sachs’ comments about his study.