Fainting

Summary

Fainting is a temporary loss of consciousness. If you’re about to faint, you’ll feel dizzy, lightheaded, or nauseous. Your field of vision may “white out” or “black out.” Your skin may be cold and clammy. You lose muscle control at the same time, and may fall down.

Fainting usually happens when your blood pressure drops suddenly, causing a decrease in blood flow to your brain. It is more common in older people. Some causes of fainting include:

• Heat or dehydration
• Emotional distress
• Standing up too quickly
• Certain medicines
• Drop in blood sugar
• Heart problems

When someone faints, make sure that the airway is clear and check for breathing. The person should stay lying down for 10-15 minutes. Most people recover completely. Fainting is usually nothing to worry about, but it can sometimes be a sign of a serious problem. If you faint, it’s important to see your health care provider and find out why it happened.

National Heart, Lung, and Blood Institute

Find an Expert

• American Heart Association American Heart Association
• Heart Rhythm Society Heart Rhythm Society
• National Heart, Lung, and Blood Institute National Heart, Lung, and Blood Institute
• National Institute of Neurological Disorders and Stroke National Institute of Neurological Disorders and Stroke

Clinical Trials

• ClinicalTrials.gov: Syncope National Institutes of Health
• ClinicalTrials.gov: Syncope, Vasovagal National Institutes of Health

Teenagers

• Dizziness and Fainting Spells American Academy of Pediatrics
• Fainting Nemours Foundation

Children

• Fainting Nemours Foundation

Patient Handouts

• Fainting Medical Encyclopedia

Start Here

• Fainting American Academy of Family Physicians
• Syncope National Institute of Neurological Disorders and Stroke

Older Adults

• Fainting (Syncope) AGS Health in Aging Foundation

Related Issues

• Fainting (Syncope) after Vaccination Centers for Disease Control and Prevention
• Syncope (Fainting) Heart Rhythm Society

Specifics

• Fainting during Urination (Micturition Syncope): What Causes It? Mayo Foundation for Medical Education and Research
• Vasovagal Syncope Mayo Foundation for Medical Education and Research

Treatments and Therapies

• Fainting: First Aid Mayo Foundation for Medical Education and Research

Journal Articles

• Fainting

Diagnosis and Tests

• Tilt Table Test Mayo Foundation for Medical Education and Research