Anxiety Nausea: Why It Happens and How to Stop It

By Molly Moloney, Psy.D.

Anxiety is an emotional and physiological state that affects the body in various ways, and nausea is one of its most common physical symptoms. Understanding why anxiety triggers nausea and how to alleviate it can help people maintain a more compassionate and empowered relationship to their bodies and emotions. This article will explore anxiety nausea through the lens of polyvagal theory and somatic therapy, two approaches that offer unique insights into the connection between our nervous system and physical symptoms.

Anxiety and Its Impact on the Body

Anxiety occurs when our body perceives a threat, activating the autonomic nervous system in preparation to deal with that danger. This is known as the fight-or-flight response, otherwise known as sympathetic activation, a survival mechanism designed to protect us (Bracha, 2004). However, when anxiety becomes chronic or overwhelming, it can lead to physical symptoms such as nausea, dizziness, gastrointestinal distress, and headaches. Polyvagal theory helps explain these responses by shedding light on how our nervous system reacts to stress and how we can regulate these reactions to restore balance (Porges, 2009).

Why Nausea is a Common Symptom of Anxiety

Polyvagal Theory and the Body’s Response to Stress

According to polyvagal theory, developed by Dr. Stephen Porges, the autonomic nervous system is divided into three distinct branches: the ventral vagal, sympathetic, and dorsal vagal states (Porges, 2009). Each of these systems governs different states of arousal in response to perceived safety or threat.

Ventral vagal activation is associated with feelings of safety, calm, groundedness, presence, and connection.

Sympathetic activation triggers the fight-or-flight response, causing a surge of energy as the body prepares to either confront or escape the danger. The body undergoes a cascade of changes in this state, from increased blood pressure, heart rate, adrenaline, pupil size, and defensive responses, to decreased digestion, relational ability, fuel storage, and immune response. The muscles often tense, preparing to either fight or flee.

Dorsal vagal activation, often linked to a state of "shutdown" or immobilization, is activated when the threat feels overwhelming and inescapable, which can manifest as nausea, dizziness, and disconnection. In this state, the body increases fuel storage, endorphins to numb pain, and begins to preserve metabolic resources, while it decreases heart rate, blood pressure, muscle tone, social behavior, and sexual response (Porges, 2011). 

When anxiety hits, it often activates either the sympathetic or dorsal vagal system, depending on the perceived level of threat. The physical sensation of nausea is one of the ways the body reacts when it feels overwhelmed or unsafe and occurs due to the physiological changes induced by the shift in autonomic nervous system state. In this context, nausea is part of the body’s effort to disengage from stress by resorting to a survival strategy of fight, flight, freeze, or fawn (Dana, 2018).

Causes of Anxiety Nausea

How Anxiety Affects the Digestive System

The gut-brain axis, which is the bidirectional communication network between the brain and the digestive system, plays a critical role in anxiety- related nausea (Mayer et al., 2015). The vagus nerve, a key component of this axis, regulates digestion. When the perception of threat leads to anxiety and therefore activation of the autonomic nervous system, it disrupts normal digestive processes by slowing down or halting the digestive system entirely. This is why we often feel queasy or nauseated during stressful situations. During the fight-or-flight response, the sympathetic nervous system redirects energy away from functions that aren’t essential for immediate survival, such as digestion (Sapolsky, 2004). As a result, digestion slows down or stops, often causing nausea. The energy that would normally go to processing food is instead directed toward increasing heart rate and muscle tension.

Stress Hormones and Their Role in Nausea

When the brain detects a threat, it releases stress hormones such as adrenaline and cortisol. These hormones alter the function of the gut by decreasing blood flow and slowing down digestion, making it difficult for the body to process food efficiently (Sapolsky, 2004). The result is nausea, bloating, or even vomiting. Polyvagal theory suggests that the more regulated and safe the body feels, the less likely it is to experience these disruptive symptoms (Porges, 2011).

Anxiety Disorders Associated with Nausea

Nausea is often present in people with anxiety disorders such as generalized anxiety disorder (GAD), panic disorder, and post-traumatic stress disorder (PTSD). These conditions keep the nervous system in a prolonged state of dysregulation, which increases the likelihood of experiencing nausea and other digestive issues (American Psychiatric Association, 2013).

Symptoms Related to Anxiety Nausea

Physical Symptoms: Nausea, Dizziness, Headaches

When the nervous system is dysregulated, as polyvagal theory suggests, physical symptoms can include nausea, dizziness, headaches, or a combination of these (Dana, 2018). The dorsal vagal state of immobilization can trigger these symptoms when the body senses it needs to shut down to avoid further stress or harm.

Mental and Emotional Symptoms: Anxiety-Induced Nausea

Nausea triggered by anxiety can lead to a feedback loop, where the fear of nausea causes more anxiety, further worsening the nausea. This cycle keeps the body stuck in a state of dysregulation, making it harder to return to a calm, regulated state (Ogden & Fisher, 2015).

When Nausea is Mild vs. Severe

Anxiety nausea can range from mild to severe, depending on the level of nervous system activation. When the body is in a mild state of dysregulation, nausea may come and go. In a more severe state of threat perception, nausea may be more intense and persistent and can even lead to chronic gastrointestinal conditions.

Immediate Relief for Anxiety Nausea

Deep Breathing Exercises

Somatic therapy focuses on regulating the nervous system through techniques such as deep breathing. Deep breathing exercises activate the parasympathetic nervous system, particularly the ventral vagal system, which promotes a sense of calm and can alleviate nausea (Ogden & Fisher, 2015).

Staying Hydrated and Eating Mild Foods

Drinking water and eating bland foods like crackers can help settle the stomach, especially if the digestive system is sluggish from stress. Avoiding heavy, greasy, or spicy foods can prevent further nausea.

Natural Remedies: Ginger, Peppermint, and Aromatherapy

Natural remedies such as ginger and peppermint have been shown to soothe nausea (Smith, 2018). Aromatherapy using calming scents like lavender can also help the individual find a felt sense of safety.

Long-Term Strategies to Manage Anxiety and Nausea

Lifestyle Changes: Exercise, Sleep, and Diet

Regular exercise, adequate sleep, and a balanced diet are key to regulating the nervous system. Exercise, in particular, helps discharge excess sympathetic activation, preventing the buildup of anxiety-related symptoms like nausea (Dana, 2018).

Mindfulness and Meditation Practices

Mindfulness and meditation are effective tools for calming the nervous system. Somatic practices such as body scanning, where you pay attention to sensations in the body without judgment, can help identify and release tension, reducing anxiety nausea (Kabat-Zinn, 1990).

Cognitive Behavioral Therapy (CBT) and Somatic Therapies

CBT can be helpful for changing thought patterns that contribute to anxiety, reducing the feedback loop between anxiety and nausea, while somatic therapies like Somatic Experiencing or trauma-informed yoga focus on physical regulation to reduce anxiety symptoms, including nausea (Levine, 1997).

References

American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders* (5th ed.). American Psychiatric Publishing.

Bracha, H. S. (2004). Freeze, flight, fight, fright, faint: Adaptationist perspectives on the acute stress response spectrum. CNS Spectrums, 9(9), 679-685.

Dana, D. (2018). The polyvagal theory in therapy: Engaging the rhythm of regulation. W.W. Norton & Company.

Kabat-Zinn, J. (1990). Full catastrophe living: Using the wisdom of your body and mind to face stress, pain, and illness. Dell Publishing.

Levine, P. A. (1997). Waking the tiger: Healing trauma. North Atlantic Books.

Mayer, E. A., Tillisch, K., & Gupta, A. (2015). Gut/brain axis and the microbiota. Journal of Clinical Investigation, 125(3), 926–938.

Ogden, P., & Fisher, J. (2015). Sensorimotor psychotherapy: Interventions for trauma and attachment. W.W. Norton & Company.

Porges, S. W. (2009). The polyvagal theory: New insights into adaptive reactions of the autonomic nervous system. *Cleveland Clinic Journal of Medicine, 76(Suppl 2), S86–S90.

Porges, S. W. (2011). The polyvagal theory: Neurophysiological foundations of emotions, attachment, communication, and self-regulation. W.W. Norton & Company.

Sapolsky, R. M. (2004). Why zebras don’t get ulcers: An updated guide to stress, stress-related diseases, and coping (3rd ed.). Holt Paperbacks.

Smith, J. A. (2018). A systematic review of the effects of ginger on nausea and vomiting in human studies. The Journal of Alternative and Complementary Medicine, 24(8), 657–663.