Stress

Stress is the body's physical and psychological response to demands or threats, real or perceived, that exceed a person's sense of their resources to cope.

The response is driven by the sympathetic nervous system and the hypothalamic-pituitary-adrenal axis, which release adrenaline and cortisol to sharpen attention, raise heart rate and mobilize energy. Short bursts are adaptive. Chronic stress, in which the response never fully switches off, is associated with sleep problems, headaches, digestive complaints, high blood pressure, low mood and weakened immune function. Sources range from work and finances to caregiving, illness and major life changes.

Stress is assessed through self-report questionnaires such as the Perceived Stress Scale, and in research settings by measuring cortisol or heart rate variability. It differs from an anxiety disorder, which persists without a clear external demand. Cannabidiol has been examined in early research on stress responses, including laboratory stress tasks, and the evidence is preliminary.