Heart Health

Why people faint: From common to very rare causes

By , Executive Editor, Harvard Heart Letter

About one in seven fainting episodes stems from heart‑related problems.

There’s one simple reason behind all fainting episodes — the brain isn’t getting enough blood. But there are many possible underlying causes, ranging from common, usually harmless issues to rare, potentially serious problems.

"Fainting always should be taken seriously, so be sure to get evaluated by a doctor if you faint, particularly if you have any history of heart problems," says Dr. Jeremy Ruskin, founder of the arrhythmia service at Harvard-affiliated Massachusetts General Hospital. But even people without any previous heart issues aren’t off the hook. Sometimes syncope (the medical term for fainting) is the first sign of a previously undetected heart condition, he says.

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About the Author

photo of Julie Corliss

Julie Corliss, Executive Editor, Harvard Heart Letter

Julie Corliss is the executive editor of the Harvard Heart Letter. Before working at Harvard, she was a medical writer and editor at HealthNews, a consumer newsletter affiliated with The New England Journal of Medicine. She … See Full Bio
View all posts by Julie Corliss

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