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Blacking Out, Fainting, or Loss of Consciousness

November 24, 2020


The two main reasons for blacking out are insufficient blood flow to the brain and abnormal electrical activity within the brain (a seizure).

While both of these sound scary, in reality most episodes of blacking out are not related to life threatening health problems.

This guide is designed to provide insight into why you passed out. It is not a diagnostic tool or a substitute for evaluation by a health professional.

The questions are ones your doctor is likely to ask you. Your answers provide a path to better understanding of the common reasons for losing consciousness.

Let's begin.

Certain situations demand emergency medical care.

Do any of the following apply to you?

- Chest pain or shortness of breath before or after you passed out

- Bloody or black stools

- Severe headache

- Recent blow to the head

- A heart condition

Yes, one of those applies to me.

No, none of those apply to me.

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