New guidelines are released explaining why people faint and what medical tests they should get after a fainting episode.

Fainting could be a sign of a serious heart problem and should be evaluated by a doctor, say new guidelines from three leading heart organizations.

The guidelines, issued Thursday by the American College of Cardiology, American Heart Association and Heart Rhythm Society, are the first such guidelines on the topic.

Fainting is fairly common. About 41 percent of Americans have fainted at some point.

“This is very important because fainting impacts thousands of people every day,” said Dr. Win-Kuang Shen, a cardiologist at the Mayo Clinic in Phoenix and chair of the group that developed the guidelines. “Having these guidelines is not only good for the clinicians using them, but for everyone.”

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When someone faints, they lose consciousness due to a drop in blood pressure, resulting in a lack of oxygen to the brain.

“Fainting can be due to neurological, psychological or cardiac causes,” said Dr. Gerald Fletcher, a cardiologist at the Mayo Clinic in Jacksonville, Florida, who was not involved in writing the new guidelines.

Occasional fainting is not necessarily cause for concern, but if it’s repetitive, it needs to be addressed, he said. About 14 percent of people have recurrent fainting.

Extreme emotion, such as attending a funeral or in response to seeing blood, can trigger fainting, but it is not life-threatening, said Dr. Vincent Bufalino, M.D., a cardiologist and president of Advocate Medical Group in Naperville, Illinois, who was not involved in writing the new guidelines.

Heart-related causes are to blame for fainting more often in people over 60 compared to younger people, according to the guidelines.

This could be due to underlying heart disease or taking a higher dose of blood pressure-lowering medication, Bufalino said. Dehydration at any age can also contribute to fainting, he said.

Irregular heart rhythms and faulty heart valves are the most common heart triggers for fainting, Bufalino said.

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The new guidelines say people who faint for any reason should get a physical exam and provide their doctor with a detailed medical history.

The office visit may include an electrocardiogram, a simple, inexpensive test of the heart’s electrical activity that can help spot heart-related causes of fainting.

Competitive athletes who faint should see a doctor before resuming sports, the guidelines say. Bufalino said athletes typically pass out from dehydration or overexertion, but testing can help identify or rule out hypertrophic cardiomyopathy, an enlarged heart that could require additional treatment.

For most people who faint, additional tests, such as MRI or CT scans, are unnecessary unless the person has already been diagnosed with heart disease or a new heart issue is suspected, according to the guidelines.

Doing appropriate tests when needed and not “spending a fortune” on unnecessary tests is the best approach to fainting from a cardiovascular point of view, Fletcher said.

Although it’s important to remember that most fainting episodes are not severe, Fletcher said, checking in with your doctor to ask if it’s something to worry about is a good idea.

The original story was published on American Heart Association News.

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