Understanding How Trauma Affects the Body

Traci Freeman
Aug 4
5 min read

When people think of trauma, they often picture emotional pain or mental struggles. But trauma runs deeper than that — it leaves a physical imprint on the body. From the brain to the gut, from our stress hormones to how we process sound and touch, trauma can disrupt nearly every system in the body. Having a deeper understanding of the physical impact can lead to better regulation, more self-awareness, and self-compassion, and hopefully find ways to support the body.

To understand this means to understand trauma. Trauma can be many things, as well as personal to each individual. It can be a big event, a small event, microaggressions, or ongoing exposure.

Here are some forms of trauma: (This list is not exhaustive)

Physical abuse or harm, or witnessing this, particularly on an ongoing basis
Substance abuse, or being in a relationship with an addict (alcohol, drugs, or food)
Verbally assaulted, abused, degraded, put down, or violated
Experiencing or witnessing an intense event often feels life-changing and is possibly accompanied by a loss of control
Losing a loved one, including friends, family, or pets
Not having consistent care in your household, physical needs not met, neglect, lack of food, or shelter
Being in an unhealthy relationship (familial, romantic, professional, or friendship) that causes you to feel depressed, anxious, scared, nervous, or afraid, particularly on a consistent basis

1. Trauma Reshapes the Brain

The brain is the body’s command center, and trauma can physically change how it works.

Hippocampus – This area plays a crucial role in memory and learning. Chronic trauma can shrink the hippocampus, making it harder to form and recall memories. Studies have shown significantly reduced volume in this region among PTSD patients (Bremner, 2006). What does this mean for you? This process can be inefficient, leading to fragmented or painful memories. This can also result in difficulty with everyday and episodic memory recall in individuals with PTSD.

Amygdala – Responsible for fear and emotion, the amygdala becomes overactive in response to trauma. This leads to a heightened sense of danger and increased anxiety.

Prefrontal Cortex – This region controls decision-making and emotion regulation. Trauma weakens its function, which explains why trauma survivors may struggle with focus, impulse control, and managing stress (Van der Kolk, 2014).

2. The Nervous System Stays on High Alert

Trauma affects the autonomic nervous system, especially the balance between the sympathetic (“fight or flight”) and parasympathetic (“rest and digest”) responses.

In trauma survivors, the body often stays locked in a high-alert state: racing heart, tense muscles, hypervigilance, and sleep issues. Others may shut down entirely, feeling numb or emotionally frozen — a state known as dorsal vagal shutdown ( Van der Kolk, 2014).

This dysregulation is the body’s survival response, but it becomes harmful when it persists.

3. Digestion and the Gut Suffer

The gut and brain constantly communicate through the gut-brain axis. Trauma disrupts this pathway.

Common digestive issues linked to trauma include IBS, bloating, and nausea. Studies have linked early life stress to a higher risk of IBS in adulthood (Chitkara et al., 2008). Trauma also alters gut microbiota, which can influence mood and immunity (Foster & Neufeld, 2013).

4. Immune System and Inflammation Rise

Cortisol is a natural response to a threat, danger, or stress. The body is not meant to stay in this state for long periods of time. So when there is chronic stress or trauma, it can begin to weaken the immune system and increase inflammation. This may cause depression, fatigue, anxiety, a feeling of sluggishness, or weight gain. While every physical body is different, the research supports negative long-term effects of chronically elevated levels.

PTSD patients often show abnormal immune responses, including elevated inflammatory markers and increased risk of autoimmune diseases (Pace & Heim, 2011).

5. Hormones and Reproductive Health Are Affected

Trauma affects the endocrine system, which regulates the production and release of hormones. It can disrupt menstrual cycles, lower fertility, and interfere with reproductive hormones in both men and women. Trauma can also cause epigenetic changes—altering how genes are expressed in future generations (Yehuda & Bierer, 2009)

6. Trauma Alters the Senses

Trauma can also alter how we perceive sensory input — including sound, light, touch, and movement. Many survivors or people who experience chronic trauma become overly sensitive to loud sounds, bright lights, or physical touch. This is called sensory over-responsivity. Others may feel numb or disconnected. In children, early trauma affects how the brain integrates sensory input, which can impact learning and social skills.

What next?

If you’ve experienced trauma, it doesn’t mean you’re broken. It means your body has adapted to survive. It is designed to protect you, so it’s doing its job, and it has an impact. Healing trauma wounds is a personal journey and can include many things.

Therapy - talk, art, somatic, CBT, DBT, or group
Mindfulness - restoring the body to a calm state, breathing, and removing yourself from the harm
Journaling - allowing all your feelings, emotions, impact, ongoing thoughts or ruminations to have space. Oppressing these does not make them go away, so giving them space allows them to be reflected on and addressed
Understanding cycles - working with your family of origin history, communication cycles in your relationships, behavioral patterns, and belief systems. Often this is done in a therapeutic setting.
Self compassion - not internalizing that this is your fault, you deserved this, you are not a good person because this happened, but instead learning to be kind, compassionate, and empathetic with yourself. The healing begins with how you experience and see yourself.
Reframing beliefs - Cognitive Behavioral Therapy, Parts Work, and Trauma Therapy help a person identify the core beliefs that have evolved from the trauma, and then work on how to manage them.

If you know someone you know is experiencing chronic trauma, especially in the form of physical, sexual, or emotional abuse - PLEASE seek out help. You are worth it!