Benjamin Wedro, MD, FACEP, FAAEM
Dr. Ben Wedro practices emergency medicine at Gundersen Clinic, a regional trauma center in La Crosse, Wisconsin. His background includes undergraduate and medical studies at the University of Alberta, a Family Practice internship at Queen's University in Kingston, Ontario and residency training in Emergency Medicine at the University of Oklahoma Health Sciences Center.
Melissa Conrad Stöppler, MD
Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.
In this Article
- Fainting (syncope) Facts
- Introduction to fainting (syncope)
- What causes fainting (syncope)?
- Heart rhythm changes
- Heart structural conditions
- Heart valve conditions
- Sudden cardiac death
- Postural hypotension
- Vasovagal syncope
- Orthostatic hypotension
- Vertebrobasilar artery disease
- Electrolyte imbalance
- Other medications and drugs
- What are the signs and symptoms of fainting (syncope)?
- How is fainting (syncope) diagnosed?
- What is the treatment for fainting (syncope)?
- Can fainting (syncope) be prevented?
Heart structural conditions
Structural problems with the heart can cause fainting or syncope, either because there is a problem with the ability of the heart to adequately pump blood or because of valve problems. When the heart muscle becomes damaged or inflamed it may not have the ability to pump blood to meet the body's needs. Examples include a heart attack (myocardial infarction) or cardiomyopathy, in which the heart muscle weakens.
Heart valve conditions
Abnormalities with the heart valves can also cause fainting or syncope. The valves allow blood to go in the proper direction when the heart pumps. Valve diseases may include abnormal narrowing (stenosis) or leakage (insufficiency or regurgitation). Either situation can cause issues with maintaining adequate blood flow to the body.
Sudden cardiac death
In young people, especially athletes, fainting or syncope can occur because of abnormal thickening of parts of the heart muscle (hypertrophic cardiomyopathy). This may obstruct blood when it tries to leave the heart, especially when the heart is asked to beat harder during exercise. Sudden death in athletes may be foreshadowed by episodes of syncope.
Loss of intravascular fluid, that is the blood and water within the blood vessels, can also cause fainting or syncope. Usually, fainting will occur when a person stands up quickly from a lying or sitting position and there isn't enough time for the body to compensate by making the heart beat quicker, or having the blood vessels constrict to maintain the body's blood pressure and blood flow to the brain. This is referred to as postural hypotension.
Next: Vasovagal syncope
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