Fainting: Vagal Reaction
Fainting (syncope) is a temporary loss of consciousness. It’s also called passing out. It occurs when blood flow to the brain is reduced. Your health care provider believes that your fainting was because of a vagal reaction. This is usually not a sign of serious disease.
A vagal reaction causes your pulse to slow down or the blood vessels to expand. This causes your blood pressure to fall. Less blood goes to your brain if you are standing or sitting. That results in dizziness, near-fainting, or fainting.
Common causes of fainting include sudden fear, severe pain, emotional stress, overexertion, overheating, quick movement or position changes, hunger, nausea or vomiting, and prolonged standing. Lying or sitting down right away and elevating your legs and feet can often stop the reaction before you pass out.
Home care
Follow these steps when caring for yourself at home:
-
Get plenty of rest. Go back to your normal activities as soon as you are feeling back to normal.
-
Stay hydrated and avoid skipping meals.
-
If you feel lightheaded or dizzy, lie down right away and elevate your legs.
Follow-up care
Follow up with your health care provider, or as advised.
Call 911
Call 911 if any of the following occur:
-
Another fainting spell that’s not explained by the common causes listed above
-
Pain in your chest, arm, neck, jaw, back, or abdomen
-
Shortness of breath
-
Severe headache or seizure
-
Your heart beats very rapidly, very slowly, or irregularly (palpitations)
Online Medical Reviewer:
Marianne Fraser MSN RN
Online Medical Reviewer:
Rajadurai Samnishanth Researcher
Online Medical Reviewer:
Robyn Zercher FNP
Date Last Reviewed:
1/1/2025
© 2000-2025 The StayWell Company, LLC. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.