Hyperarousal

Hyperarousal refers to a state of heightened physiological and cognitive arousal characterized by increased sympathetic nervous system activity. It commonly involves a raised heart rate, blood pressure, faster breathing, heightened sensory sensitivity, irritability, and vigilance. Sleep disturbance, such as trouble falling or staying asleep, is frequent. Hyperarousal can occur as part of posttraumatic stress disorder, acute stress disorder, generalized anxiety disorder, and chronic insomnia, and may also arise from stimulant use, caffeine, medical conditions, or substance withdrawal.

The underlying mechanisms involve amygdala hyperreactivity and dysregulation of the hypothalamic-pituitary-adrenal axis, with reduced top-down control from the prefrontal cortex. This neural pattern promotes a persistent state of alertness to potential threats, creating a cycle in which attention remains oriented toward threat, sleep is disrupted, and daytime functioning is affected.

Common symptoms include irritability, difficulty concentrating, hypervigilance, an exaggerated startle response, and non-restorative sleep. Some individuals may experience chest tightness, dizziness, sweating, or tense muscles. In clinical assessment, hyperarousal is a core component of PTSD and is evaluated using self-report scales and clinician-administered instruments; for PTSD, it is one of the diagnostic symptom clusters (alongside intrusion, avoidance, and negative mood or cognition).

Treatment focuses on addressing the underlying condition and reducing arousal. Psychotherapies such as cognitive behavioral therapy and exposure-based approaches, along with sleep-focused interventions, are used. Pharmacotherapy may include selective serotonin reuptake inhibitors or serotonin-norepinephrine reuptake inhibitors; prazosin can be helpful for PTSD-related nightmares. Lifestyle measures (reducing caffeine and alcohol, stress management, mindfulness) also support reduction of hyperarousal. Prognosis improves with appropriate treatment and management of contributing factors.