Boo! Medical experts describe fear’s effects
UF College of Medicine experts weigh in on how fear affects the mind and body
Oct. 29, 2025 — A cockroach in the bathroom at night. The sound of a door opening when you know no one else is home. Watching too many true-crime shows. Snakes (outside). Rats (inside).
Fear is a many-splendored thing, and University of Florida College of Medicine experts are weighing in on how it affects the mind and body.
Regardless of what you are afraid of — or your age — feeling scared is a normal emotion in response to danger. There is nothing wrong with being afraid of a clown. It’s when you begin to avoid the linen closet for worry a clown might be hiding there that trouble sets in.
“Fear is a normal reaction to danger happening in real-time,” said Carol Mathews, M.D., the Donald R. Dizney Chair of Psychiatry at the UF College of Medicine. “Something like a phobia, or when fear begins to interfere with daily life, is different.”
Phobias can stem from an experienced event, with some rational basis. Add anxiety into the mix — fear of a potential threat, as opposed to a tangible one — and the possibilities multiply.
“Some people will have panic attacks, which are an anxiety phenomenon,” Mathews said. “They can be triggered by something like driving over a bridge, or experiencing a traumatic event like a car accident, or even occur without an inciting incident, like in the middle of the night.”
Notably, panic attacks can happen in many contexts, but to have a diagnosis of panic disorder requires that you not only have recurring panic attacks, but you also have a sense of anticipatory anxiety about an episode happening again, or avoid places where you’ve previously had one. For some, panic attacks are exclusively physical events that make you feel like you’re going to die. (You won’t.) This is one of the most common myths Mathews debunks. For others, anxiety manifests without many physical symptoms: just swirling, anxious thoughts without an identifiable impact on the body.
Fortunately, fear is within your control, despite how unlikely that seems in the moment. Mathews encourages patients to remember there are ways we can manage our brain.
“You can’t just mind-meld your way out of a panic attack,” she said, “but there are many things you can do to help manage them, and certainly to treat them.”
Mindfulness — a gold standard of therapeutic first-response — and biofeedback, a kind of mind-body technique that helps you pay attention to your heart rate and breathing patterns during intense physiological and psychological stress, both offer ways to shush the noise a scared brain can make.
There’s a reason breathing exercises are so often used to quell panic. They help your galloping heart slow down to a trot. And urban legends where someone’s heart stops from fright? They’re just that — urban legends. But like most tall tales, they have a grain of truth.
“Sometimes, when you’re reacting to an intense trauma, like learning that a parent died, your heart rate goes up, your blood pressure goes up, you release all of these catecholamines from your brain,” said Juan Aranda, M.D., chief of cardiology in UF’s Division of Cardiovascular Medicine. “These neurotransmitters and hormones elicit the fight-or-flight response and can overwhelm the heart.”
This can weaken the heart, referred to as stress-induced cardiomyopathy. Most of the time, this occurs in patients with conditions like hypertension or diabetes.
“I’ve never heard of someone simply dying, but I have had patients come in with palpitations, chest pains, breathing problems,” Aranda said. “We probably see a stress-induced cardiomyopathy or stress-induced injury to the heart once every other month.”
Most of the time, Aranda says, a blood workup reassures everyone, patient included, that they didn’t have a heart attack. Medication and time help the heart recover. Finding ways to overcome that fear, or deal with it, can help prevent a recurrence. He recommends seeking help from others — even if it’s just talking about it.
“We are all human, and subject to stress and our own individual fears,” Aranda said. “I try to remember everything I have gotten through and let this calm me.”
Those of us who have lingering fear from scary memories, however, might be pleased to know that the unnerving recollections occupy specific real estate in our brains. When biochemist and molecular biologist Sathyanarayanan Puthanveettil, Ph.D., and his team decided to look at long-term memories, they went with those that were the strongest: our memories of fear.
“Our brains remember the contexts in which scary things occur,” said Puthanveettil, an associate professor at The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology. “Now, we’re trying to understand what it is about this mechanism that enables it to last for so long. What makes the fear memory stay for a period of time.”
When we learn or experience something new, or even come down with an illness, new RNAs are produced, Puthanveettil said. Some of the RNAs produce proteins. Others don’t. These long, noncoding RNAs coordinate cell activities instead — but we’re still learning about them.
“In humans, there are more than 100,000 different noncoding RNAs,” Puthanveettil said. “We found that a particular link, that one of my lab members named SLAMR, is specific to memories of fear in mice.”
As researchers studied fear memories and spatial memories, they found that inhibiting SLAMR affected fear memories but left spatial memories intact. Now, the team wants to understand why that is.
“Fear is an extremely important emotion,” Puthanveettil said. “We’re looking forward to understanding what allows the memory to last for so long.”
Some of our strongest memories of fear might come from some of our earliest experiences with it. Other times, the experience incites a lasting change — be it a phobia, anxiety or an anxiety disorder, like obsessive-compulsive disorder. Others may be aware of their OCD, but unable to tie it to any early experience.
“It varies by individual,” said Joseph McNamara, Ph.D., chief of the psychology division in the UF Department of Psychiatry and director of the OCD Treatment Program. “Sometimes people can point to a specific incident that happened, and other times people have no idea.”
Ultimately, knowing doesn’t make much difference, McNamara said. By the time patients see his team, unhealthy anxieties have had time to fester. The average time between OCD symptoms manifesting and treatment beginning is seven years.
Some of the most common anxieties include contamination, social-related anxieties (worries about rejection), health-related conditions (dreading cancer you don’t have) and safety-related anxieties (going back to be sure the stove is turned off).
Exposure-based techniques ask the patient to progressively approach what they’re afraid of and sit in the cognitive dissonance of their feared, worst outcome not happening. By and by, the patient can better tolerate the thing that frightens them.
“If someone is struggling, I want them to know that there’s help,” McNamara said. “People can struggle for a long time, or lose hope. But there are really effective, robust treatment options available.”
When he’s working with exposure-therapy patients McNamara often asks: “Who’s getting stronger: You or the fear?”
As the session ends, more often than not, fear is no longer calling the shots.
