The Effects of Fear on the Brain and Body

Jun 1, 2022 | Fear, Anxiety, Blog, Mental Health, Panic, Stress

Fear is one of the most basic and powerful human emotions. It can be critically helpful in situations where we need to protect ourselves from danger. But did you know that fear can also have a negative impact on our health? Fear can become a problem when it is chronic and debilitating. In this blog post, we will explore the effects of fear on the brain and body and discuss how fear works when our brain and body perceive a threat. 

How Fear Works in Modern Daily Life

A perceived threat often triggers the emotion known as fear. When we experience fear, our bodies go into what is known as the “fight-flight-freeze” response. This survival mechanism helped our ancestors avoid being eaten by predators while hunting for sustenance. It signals our bodies to react to danger to keep us safe.

Once our body senses a potential danger, hormones release causing:

  • Shut down of bodily systems that aren’t needed to survive, such as the digestive tract
  • It heightens the function of bodily systems that can help us survive, such as eyesight. Fear also increases blood flow and heart rate to activate our muscles to help us run faster.
  • Hormone flow increases to the amygdala in the brain to help us zero in on the potential risk.

The “amygdala hijack,” a common nickname for the overactive state the brain goes into when in danger, causes our thoughts to shift away from rationality as a protective measure. It leads the brain to perceive (and remember) a threatening or dangerous event as negative. Because our attention shifts toward the present threat, our brain absorbs all it can: smells, sounds, weather, colors, etc. Therefore, when the brain recognizes one of those negatively stored factors, it will grow alert to the potentiality of a new threat.

In today’s world, a fear response can be triggered by things like public speaking or heights, anything that makes us feel like we are in danger or on high alert.

Effects of Fear on the Brain and Body

Constant fear—whether of physical dangers in one’s environment or threats perceived to exist—can have negative consequences. Those who live in fear can develop negative thought patterns that hinder them and physical ailments due to the body persistently being on high alert. There are numerous effects of fear on the brain and body, both short-term and long-term.

The Brain

Three aspects of cognitive function impacted by fear are memory, brain reactivity, and mental health.

  • Memory: Fear can cause damage to the hippocampus, a part of the brain that plays a crucial role in regulating fear and anxiety. This damage impairs the formation of long-term memories, making it even more difficult for someone to control their emotions or causing them to feel hyper-vigilant on a regular basis. The world seems pervasively frightening to someone plagued by fear, and their memories confirm that proposition.
  • Brain reactivity: Chronic fear can impact cognitive abilities, making it harder to think clearly or make decisions. It can also lead to problems regulating emotions, reading non-verbal cues or other information presented to us, reflecting before acting, and acting ethically. This can leave us susceptible to intense emotions and impulsive reactions. Fear’s impact on the brain can leave an individual unable to act appropriately or rationally.
  • Mental Health: A long-term consequence of fear on the brain (and the body) is its negative influence on mental health. Chronic fear can lead to an array of challenging mental health concerns, with some being increased or chronic fatigue, post-traumatic stress disorder, or major depressive disorder.
The Body

In the short term, fear triggers a release of stress hormones like adrenaline and cortisol. These hormones increase heart rate, blood pressure, and respiration. When a person chronically experiences the physical symptoms of fear, it can lead to cardiovascular damage, decreased fertility, accelerated aging, and gastrointestinal issues among others. It can also cause specific conditions such as heart disease and autoimmune disorders.

Intergenerational Trauma

It is also important to note that one can experience anxiety or fear in response to trauma they did not directly experience. Experts often refer to this phenomenon as intergenerational trauma, generational trauma, or inherited trauma.

The research on intergenerational trauma is still evolving, but people can inherit the impact of trauma from their ancestors. For example, some descendants of Holocaust survivors may experience anxiety, depression, and chronic fear at increased rates.

The descendants of survivors of other massive traumas, such as slavery or genocide, often report symptoms like those experienced by people who directly endured the traumas themselves, complicating their healing and health. Communities of African Americans, Indigenous people, and other marginalized groups can experience a shared sense of grief and ongoing fear. Discrimination, brutality, and racism can also perpetuate inherited trauma.

Coping With Chronic Fear

If you are struggling with chronic fear, there are steps that you can take to manage it. One of the most important is to understand where your anxiety comes from. Once you identify the source of your fear, you can start working toward healing the impacts fear has had on your brain and body. Many helpful therapies are available for managing chronic fear, including cognitive-behavioral therapy (CBT) and exposure therapy.

It is important to remember that there is hope! While it may take a bit of committed effort, you can manage your fear and improve your quality of life. It is not impossible, and support is available. You do not have to weather the storm alone. Please don’t hesitate to contact us today if you are ready to conquer your fears and take back control of your life and well-being.

New Dimensions Can Help!

If you or someone you know is experiencing any of the above symptoms or problems, New Dimensions can help. Our team of experienced therapists and psychiatrists can help you overcome these challenges and help you develop the skills you need to thrive. To schedule a complementary assessment or to find out more about our programs, contact us at 1-800-685-9796.

Our affiliate, MHThrive, provides Individual Therapy, Couples and Marriage Counseling, and Family Therapy at our locations in Katy, The Woodlands, and the Clear Lake area of Houston, Texas. We also provide telehealth therapy for anyone who resides within the State of Texas. To schedule an appointment with one of the MHThrive therapists, contact us at 713-477-0333 or visit to learn more.