What should you know about fainting due to stress?

A frightening sight, sudden pain, emotional shock or distress may activate the body’s fainting reflex. Blood vessels widen and the heart may slow, so less blood reaches the brain briefly. Warning symptoms can include warmth, sweating, nausea, dizziness, greyed or narrowed vision and ringing in the ears. Anxiety can also cause rapid breathing, which may worsen light-headedness.

Stress may be the setting rather than the whole explanation. A clinician should consider hydration, food intake, medicines, anaemia and heart rhythm, especially if the event was unexpected or different from earlier episodes.

Lie down promptly, preferably with your legs raised, and move away from hazards. If lying down is impossible, sit with your head lowered. Loosen restrictive clothing and breathe slowly and comfortably; do not deliberately over-breathe into a bag. Stay down until the warning passes, then stand in stages. A trusted person can stay nearby and record what happened.

Call emergency services for trouble breathing, chest pain, severe injury, seizure, abnormal breathing, persistent confusion or failure to wake. Urgent assessment is needed if fainting happens during exercise, while lying down, without warning or alongside a rapid or irregular heartbeat. Book a medical review after a first faint, repeated episodes or any blackout with a new pattern.

Ask whether the episode fits a reflex faint and whether you need blood pressure, heart rhythm or blood tests. Describe the emotional trigger, posture, warning symptoms, recovery, medicines, fluid intake and any injuries.