Trauma can deeply affect sleep, leading to nightmares and even sleep paralysis. When the brain struggles to process traumatic memories, it can replay them in vivid, distressing dreams. This can heighten night-time anxiety, making it harder to fall and stay asleep. Sleep paralysis, where the body temporarily remains immobilised upon waking, is also linked to trauma, as the nervous system remains stuck in a hypervigilant state. Both experiences can reinforce fear and exhaustion, creating a cycle of disrupted sleep. Addressing trauma through nervous system regulation and therapeutic support can help restore healthier sleep patterns and a greater sense of safety.
The Science of Sleep and Trauma
The nervous system plays a crucial role in how the body responds to trauma, particularly in regulating sleep. When someone experiences trauma, the autonomic nervous system (ANS) can become dysregulated, leading to a heightened state of hyperarousal or hypervigilance. This keeps the body in a persistent fight-or-flight state, making it difficult to relax and fall into deep, restorative sleep.
Hyperarousal can lead to insomnia, frequent awakenings, and restless sleep, while hypervigilance causes an exaggerated startle response and difficulty in transitioning into deeper sleep stages. Instead of feeling safe enough to enter a relaxed sleep state, the brain remains on high alert, scanning for danger even in the absence of real threats.
The REM (Rapid Eye Movement) cycle is particularly affected by trauma. REM sleep is critical for emotional processing and memory consolidation. However, trauma survivors often experience REM fragmentation, leading to intense nightmares, flashbacks, and disrupted sleep. Because traumatic memories are often stored in fragmented and unprocessed ways, the brain may struggle to integrate them properly during REM sleep, resulting in distressing dream content. Over time, this cycle of poor sleep and re-experiencing trauma at night can reinforce symptoms of PTSD, anxiety, and emotional dysregulation, making recovery more challenging.
Why Trauma Triggers Nightmares
The amygdala and hippocampus—parts of the brain involved in emotion regulation, memory processing, and threat detection—play key roles in how traumatic memories are stored and recalled, directly influencing the occurrence of nightmares. The amygdala, responsible for processing fear and emotional responses, becomes hyperactive after trauma, making the brain more sensitive to perceived threats. Meanwhile, the hippocampus, which organises and contextualises memories, often struggles to properly integrate traumatic experiences, leading to fragmented and disorganised recollections.
Because trauma memories are often stored in a raw, unprocessed state, they can resurface during sleep as disturbing nightmares. The brain attempts to process these unresolved experiences during REM sleep, but due to the heightened emotional charge of trauma, these dreams can become distressing and repetitive. Instead of resolving the trauma, nightmares can reinforce the emotional intensity, keeping the nervous system in a state of hyperarousal.
Research shows a strong link between PTSD and frequent nightmares. Studies indicate that 70-90% of people with PTSD report recurring nightmares, compared to about 5% in the general population. These nightmares often replay aspects of the trauma, sometimes in literal form, other times in symbolic or exaggerated ways. This repeated night-time distress can worsen sleep quality, increase daytime anxiety, and make recovery from trauma more challenging.
Understanding Sleep Paralysis and Trauma
Sleep paralysis is a phenomenon where a person becomes temporarily unable to move or speak while falling asleep or waking up. It is often accompanied by a sense of pressure on the chest, difficulty breathing, and, in some cases, vivid hallucinations. Though generally harmless, sleep paralysis can be extremely distressing, especially for individuals with a history of trauma.
A dysregulated nervous system, often seen in those with post-traumatic stress, may contribute to sleep paralysis episodes. Trauma can keep the body in a heightened state of hypervigilance, making it difficult to transition smoothly between sleep stages. Normally, during REM sleep, the body experiences temporary muscle paralysis (known as atonia) to prevent acting out dreams. However, when the nervous system is dysregulated, this paralysis may persist momentarily upon waking, creating the sensation of being trapped in one’s own body.
Hyperalert states, common in trauma survivors, can exacerbate this experience. The brain, primed to detect threats, may misinterpret harmless sleep-related sensations as danger, increasing feelings of panic and helplessness. This can lead to a cycle where fear of sleep paralysis worsens overall sleep quality, making it more likely to occur.
Breaking the Cycle: Managing Nightmares and Sleep Paralysis
Regulating the nervous system before bed can significantly reduce nightmares and sleep paralysis by shifting the body from a state of hyperarousal (sympathetic dominance) to relaxation (parasympathetic activation). The vagus nerve plays a crucial role in this process, as it helps regulate stress responses and promote a sense of safety. Here are four effective strategies to support nervous system regulation before sleep:
Mindfulness and Grounding – Engaging in mindfulness practices, such as body scans or guided imagery, helps shift attention away from intrusive thoughts and calms the amygdala. Focusing on present sensations reassures the brain that there is no immediate threat, reducing night-time hypervigilance.
Breathwork for the Vagus Nerve – Deep, slow breathing stimulates the parasympathetic nervous system and promotes relaxation. Try the 4-7-8 technique: inhale for four seconds, hold for seven, and exhale for eight. This slows the heart rate, activates the vagus nerve, and signals safety to the body.
Progressive Muscle Relaxation (PMR) – Tensing and then slowly relaxing muscle groups releases stored tension and calms the body. This technique reduces physical signs of stress, helping prepare the nervous system for deep sleep.
Optimising Sleep Hygiene – Creating a bedtime routine that reduces stress can improve sleep quality. Avoiding screens before bed, dimming lights, and engaging in calming activities (like journaling or gentle stretching) signal to the brain that it is safe to rest.
By consistently incorporating these strategies, individuals can create a sense of safety, consistency, and stability at night, reducing the likelihood of traumatic nightmares and sleep paralysis.
Getting Help with Trauma-Informed Approaches
There is no shame in seeking support to heal from the complex effects of trauma. Trauma impacts both the mind and body, and its symptoms—such as nightmares, hypervigilance, and sleep paralysis—are not simply psychological but deeply rooted in the nervous system. Approaching recovery through a trauma-informed lens is key to long-term healing.
Therapies that focus on nervous system regulation can be especially effective in addressing trauma-related sleep disturbances. By working with the body’s physiological responses rather than against them, these therapies help individuals re-establish a sense of safety and resilience. Somatic therapies, EMDR (Eye Movement Desensitisation and Reprocessing), and mindfulness-based interventions can be particularly beneficial.
Khiron Clinics specialises in polyvagal-informed care, understanding that trauma symptoms stem from an overactive survival response in the nervous system. By focusing on restoring balance, their approach helps individuals move from states of fear and hyperarousal to greater calm and connection.
