What should you know about hypotension syncope?

Syncope is a brief loss of consciousness followed by recovery. A blood-pressure drop can reduce brain blood flow, especially after standing, prolonged stillness, heat, dehydration, pain, or emotional stress. Some episodes are linked to a slow heart rate or another heart problem, so fainting should not be dismissed as simple low blood pressure without assessment.

Warning symptoms may include warmth, sweating, nausea, tunnel vision, ringing in the ears, or sudden weakness. Not everyone notices a warning. A witness's description, the position of the body, duration of unresponsiveness, recovery, and any jerking or injury can help a clinician distinguish syncope from other causes.

If you feel faint, lie flat and raise your legs, or sit with your head lowered if lying down is not possible. Loosen tight clothing and move away from heat. A bystander should check breathing, protect you from injury, and place you on your side if you are breathing but remain unresponsive. Do not give food or drink until you are fully alert. Arrange medical review after an unexplained faint.

Call emergency services for fainting during exercise or while lying down, chest pain, severe breathlessness, a new heartbeat disturbance, prolonged unresponsiveness, confusion, seizure-like activity, heavy bleeding, or a significant injury. Urgent assessment is also needed when fainting is recurrent or there is known heart disease.

Ask whether your episode fits syncope, whether heart testing or blood tests are needed, and how to respond if warning symptoms return.