What Causes Somatic Symptom Disorder?

Written by Niels Barends, MSc, psychologist with more than 14 years of clinical experience treating trauma-related symptoms, anxiety disorders, emotional dysregulation, and somatic symptom disorder. Updated May 2026.

Somatic symptom disorder (SSD) usually develops through a combination of biological sensitivity, chronic stress, trauma, anxiety, emotional learning, and the way the brain and nervous system interpret physical sensations. In most cases, there is not one single cause. Instead, symptoms gradually become part of a self-reinforcing cycle involving fear, body monitoring, stress, and nervous system activation.

People with SSD experience real physical symptoms such as pain, dizziness, fatigue, gastrointestinal complaints, numbness, muscle tension, or other bodily sensations. For some individuals, these symptoms become emotionally overwhelming and start to dominate daily life. Many people spend hours monitoring their body, searching online for explanations, seeking medical reassurance, avoiding activities, or fearing that something serious has been missed.

Research suggests that vulnerability to somatic symptom disorder may increase through a combination of genetics, heightened stress sensitivity, trauma, chronic nervous system activation, childhood emotional experiences, health anxiety, and learned beliefs about illness and safety. Over time, the body itself may begin to feel unsafe or unpredictable.

In clinical practice, somatic symptom disorder often overlaps with anxiety disorders, complex PTSD, panic symptoms, depression, dissociation, health anxiety, or emotional dysregulation patterns seen in conditions such as borderline personality disorder. Understanding these overlaps is important because treatment often needs to address both physical symptom distress and underlying emotional or trauma-related patterns.

This page explains the most important known causes and contributing factors in somatic symptom disorder, including trauma, chronic stress, nervous system hyperactivation, genetics, family environment, emotional regulation difficulties, and learned fear around bodily sensations.

Somatic symptom disorder causes – Genetics and biological sensitivity

Research suggests that some people may inherit a stronger biological sensitivity to stress, anxiety, emotional distress, or bodily sensations [5],[7]. This does not mean there is one single “SSD gene,” but rather that some individuals may have a nervous system that reacts more strongly to stress or physical sensations.

Studies have found associations between somatic symptoms and biological systems involved in stress regulation, including the serotonin system and the hypothalamic-pituitary-adrenal (HPA) axis [5]. These systems play an important role in emotional regulation, stress responses, and nervous system activation.

Some people are naturally more sensitive to emotional distress, uncertainty, fear, or body-related sensations. Traits such as neuroticism — the tendency to respond strongly to stress or negative emotions — may increase vulnerability to somatic symptom disorder [7].

Importantly, inheriting a biological vulnerability does not mean someone will automatically develop SSD. Environmental stress, trauma, emotional experiences, and coping patterns also play an important role.

Somatic symptom disorder causes – Family environment and learned behavior

Children learn how to interpret emotions, stress, illness, and physical sensations partly through their environment. Research suggests that children of parents with somatic symptom patterns or high health anxiety may become more focused on bodily sensations themselves [8].

In some families, physical symptoms receive a large amount of attention while emotional experiences are less openly discussed. Over time, this may increase body monitoring and fear around physical sensations.

Research also suggests that chronic family stress, emotional neglect, hostility, rejection, or dysfunctional family environments may increase the likelihood of somatic symptoms later in life [9],[10],[11].

Somatic symptom disorder causes – Trauma and stressful experiences

Trauma appears to be one of the most important contributing factors in somatic symptom disorder for some individuals. Research suggests that approximately 50% of people with SSD reported childhood traumatization by a primary caregiver [13].

Traumatic experiences may affect how safe someone feels in their body. When the nervous system becomes highly alert for danger, normal bodily sensations may begin to feel threatening or overwhelming.

Research also suggests that PTSD symptoms, chronic stress exposure, and traumatic experiences increase the likelihood of somatic symptoms [12],[14],[15].

Trauma-related somatic symptoms may include chronic pain, dizziness, gastrointestinal symptoms, muscle tension, fatigue, numbness, panic-like sensations, or persistent nervous system activation.

In some cases, symptoms may overlap with complex PTSD, panic disorder, dissociation, or emotional dysregulation.

Because trauma can affect both the nervous system and body awareness, trauma-focused therapies such as EMDR therapy may help reduce body-related fear and somatic distress for some individuals.

Stress, anxiety, and nervous system activation

Stress and anxiety can strongly affect the body. During periods of chronic stress, the nervous system becomes more activated, which may increase muscle tension, pain sensitivity, dizziness, gastrointestinal symptoms, fatigue, heart palpitations, or other physical sensations.

For some individuals, physical sensations gradually become associated with danger. Once this happens, the body may remain in a cycle of fear, body monitoring, reassurance seeking, and hypervigilance.

This cycle can unintentionally intensify symptoms. Increased fear leads to more nervous system activation, which increases physical sensations, which then creates more fear and body monitoring.

Related mental health conditions and overlap

Somatic symptom disorder often overlaps with other mental health conditions involving stress sensitivity, fear, trauma, emotional dysregulation, or nervous system hyperactivation.

Understanding these overlaps is important because treatment may need to address both emotional and physical components of the symptom pattern.

When to seek professional help

It may be helpful to seek professional support if physical symptoms are causing persistent distress, fear, repeated reassurance seeking, body monitoring, avoidance, or disruptions in daily life.

Professional assessment can help determine whether symptoms fit somatic symptom disorder, anxiety disorders, trauma-related symptoms, panic symptoms, or another condition. Treatment can also help reduce body-related fear and improve emotional regulation and quality of life.

Frequently asked questions about somatic symptom disorder causes

References

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