Fear isn't just the mind-killer... it can actually kill your body as well. The notion of being scared to death may sound like a myth, but it does happen to people — and animals. The authors of Zoobiquity: What Animals Can Teach Us About the Health And Science of Healing examined the question in detail.


Here's what actually happens when you're so scared, you die.

Top image: Screencap from The Oblong Box (1969).

Heart attacks go up during times when there are earthquakes, financial catastrophes, and civil unrest. They also go up when soccer games go into overtime... and when people see scary movies. They happen to humans, they happen to animals, and they happen without any actual injury to your body. Bodies are designed so that they can literally be scared to death.


The Mechanics

There are a couple of ways that fear and stress can stretch out, rip up, or break a heart. The heart is a set of tubes, surrounded by muscles. The muscles support and squeeze the tubes. Blood, squeezed through the tubes, is pushing out. The muscles squeeze in.

One of the most well-known syndromes throws off the balance between those tubes and muscles. Doctors in Japan noticed that people who had persistent stress, pain, and fear, came in with symptoms of a heart attack. These were relatively healthy, young people. When the doctors looked at one of these hearts, they noticed that one of the chambers in it was grossly distended. Some doctors might have looked at the widened chamber and seen an eggplant or a light bulb. These doctors saw takotsubos — traps that fishermen used to catch octopus. They called what the patients were experiencing Takotsubo Cardiomyopathy.

The heart's muscles are wired to stay on-rhythm via the nervous system. Stress hormones, called catecholamines, are generally meant to boost muscle fitness, making them work faster and harder than they usually do, and respond with alacrity to nervous impulses. Sudden shocks, either building emotional terrors or simple startle reactions, cause stress hormones to pour out, messing with the heart's rhythm, putting more stress on certain parts of the arteries or muscles, or poisoning the muscles entirely.


Most cases of Takotsubo syndrome recovered. Some, however, had cases that so disrupted the normal rhythm of their hearts that they died of the disease. Sometimes, the ventricle actually ruptured. This, in addition to the fact that it was brought on by emotional stress, earned it the nickname Broken Heart Syndrome.

But stress and trauma don't just take out the heart. These catecholamines go tearing through all the muscles of the body. They cause muscles to burn so hard that they break down, especially skeletal muscles — the muscles that are connected to the skeletal system. As these muscles break apart, their proteins get into the blood, and from there into the kidneys. These proteins eventually overwhelm the kidneys, causing them to shut down and poisoning other areas of the body, leading to death. The process is, less poetically, called rhabdomyolysis. It happens suddenly, but more often it involves a long chase, with persistent muscle strain and emotional exhaustion.


The Deaths

Takotsubo deaths came as no surprise to one segment of the world of medicine: veterinarians. They had been dealing with deaths due to capture since the profession began. It was called "capture myopathy." Captured wild animals had a rate of death of between one and ten percent of animals captured. For high-risk animals, including most birds, the rate could climb as high as fifty percent. Over the years, as the focus has shifted from hunting to conservation, techniques have been set up to lower the rate of death. This includes using as little restraint as possible, not chasing the animals, keeping noise and movement down, and given the animal some way to move. They've also learned not to stare directly into the eyes of a captured animal for any length of time.


If the animals don't die the moment they're caught, these factors keep down the mortality rate. They also keep down the deaths in captivity. Zoos have learned to keep animals in large enclosures and give them places where they can hide from their viewers. They've also learned to keep noise down at all costs. There was a recorded instance of an opera performance in a nearby park spooking an okapi until it died. Another zoo learned better than to mix certain animals when several zebras died after being put in an enclosure with cape buffalo.


Humans experience the same sudden death as animals startled by loud noises or subjected to violent capture scenarios — just generally under different circumstances. Extreme shocks can kill people who otherwise seemed healthy. The curse of humanity is that our emotions tend to us to interpret non-capture situations the same way a zebra trapped in an enclosure with a large, intimidating animal might. Financial collapse, the death of a loved one, being trapped in a situation that triggers a phobia, or repeated abuse at school or work, trigger the same physical response that animals get in what they perceive as life-or-death situations without any hope of escape.

People who feel trapped experience capture myopathy, the same way that animals do. The body pumps out the same cocktail of drugs that, in the short term, gives muscles a burst of energy, but in the long run or when overdone, simply rips them apart. The stress continues without abatement, and the body just shuts down. A person can be literally scared to death.


The link between these two diseases was first spotted by Barbara Natterson-Horowitz, a surgeon who worked with both people and zoo animals. Both humans and animals suffer from the same physical trauma, and both kinds of trauma spring from a similar emotional source. It seems we share more of our emotional and physical responses with animals than we think.

To look in detail at these physical and emotional crossovers, and to see the kinds of health issues that humans and animals share, check out Zoobiquity: What Animals Can Teach Us About the Health and Science of Healing, by Barbara Natterson-Horowitz and Kathryn Bowers.


Via Zoobiquity, ABC, AHA, and NCBI twice.