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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.
- Fainting (American Academy of Family Physicians) Also in Spanish
-
Syncope
(National Institute of Neurological Disorders and Stroke)
Diagnosis and Tests
- Tilt Table Test (Mayo Foundation for Medical Education and Research) Also in Spanish
Treatments and Therapies
- Fainting: First Aid (Mayo Foundation for Medical Education and Research) Also in Spanish
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) Also in Spanish
- Vasovagal Syncope (Mayo Foundation for Medical Education and Research) Also in Spanish
Clinical Trials
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ClinicalTrials.gov: Syncope
(National Institutes of Health)
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ClinicalTrials.gov: Syncope, Vasovagal
(National Institutes of Health)
Journal Articles References and abstracts from MEDLINE/PubMed (National Library of Medicine)
- Article: An unthinkable cause of syncope.
- Article: Machine learning-based prediction of fainting during blood donations using donor properties...
- Article: Assessment of Canadian Syncope Risk Score in the prediction of outcomes...
- Fainting -- see more articles
Find an Expert
- American Heart Association
- Heart Rhythm Society
-
National Heart, Lung, and Blood Institute
-
National Institute of Neurological Disorders and Stroke
Also in Spanish
Children
- Fainting (Nemours Foundation)
Teenagers
- Dizziness and Fainting Spells (American Academy of Pediatrics) Also in Spanish
- Fainting (Nemours Foundation) Also in Spanish
Older Adults
- Fainting (Syncope) (AGS Foundation for Health in Aging)