If you experience severe symptoms, call 911 immediately. Every second counts during a medical emergency.
Fainting, medically known as syncope, is a temporary loss of consciousness caused by a brief interruption of blood flow to the brain. While often benign, fainting can sometimes indicate a serious underlying heart condition and should be evaluated by a healthcare provider.
This content is for informational purposes only and does not substitute professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider for medical concerns. In case of emergency, call 911 or your local emergency services immediately.
Before fainting, you may experience: • Lightheadedness or dizziness • Nausea • Pale or clammy skin • Blurred or tunnel vision • Ringing in ears • Feeling warm or sweaty After waking up, confusion, fatigue, and weakness are common.
Most common type, triggered by emotional stress, pain, or standing too long.
Caused by heart problems like arrhythmias or structural heart disease.
Occurs when standing up too quickly, causing blood pressure drop.
Triggered by specific activities like coughing, urinating, or swallowing.
Abnormal heart rhythms that disrupt blood flow to the brain.
Low blood volume from inadequate fluid intake.
Narrowed or leaking heart valves affecting blood flow.
Overreaction of the nervous system to triggers like stress or pain.
Blood pressure medications, diuretics, or other drugs.
Fainting is an emergency if it occurs during exercise, is accompanied by chest pain or palpitations, the person doesn't quickly regain consciousness, there's no pulse or breathing, or if there's a history of heart disease.
Sit or lie down immediately, lower your head between your knees if sitting, stay hydrated, and try to identify and avoid triggers. If episodes continue, see a doctor.
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January 2025
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Content based on peer-reviewed research and clinical guidelines
2. Evaluation of Syncope in the Emergency Department
Quinn JV, Stiell IG, McDermott DA, et al.
Annals of Emergency Medicine, 2021
References are reviewed and updated regularly to ensure accuracy. Last update: May 2026
Cardiologist
Cardiovascular Medicine
Dr. Chen is a board-certified cardiologist with over 15 years of experience in cardiac electrophysiology and heart rhythm disorders.
Remember: In case of a medical emergency, call 911 immediately.
This page is for informational purposes only and does not replace professional medical advice.
