Fact Checked

Fainting is abrupt, momentary loss of consciousness. If an individual faint or passes out, he/she usually falls. After he/she is lying down, most can recovery rapidly. Once fainting occurs once, it is not an issue for concern, but it is best to consult a doctor since it might also have a serious cause.

What are the possible causes of fainting?

Fainting is triggered by a drop in the flow of blood to the brain. Once an individual loses consciousness and falls or lies down, more blood flows to the brain so that he/she wakes up again.

The usual causes of fainting are not indications of a serious condition such as:

  • Vasovagal reflex which causes the heart rate to slow down and widening of the blood vessels. As an outcome, the blood accumulates in the lower body and limited blood reaches the brain. This reflex might be triggered by various factors such as pain, stress, fear, coughing, holding your breath and even urinating.
  • Orthostatic hypotension or an abrupt drop in the blood pressure when changing positions. This occurs if standing up too quickly, being dehydrated and using medications such as for high blood pressure.
    Once an individual loses consciousness and falls or lies down, more blood flows to the brain so that he/she wakes up again.

The fainting due to vasovagal reflex is easy to predict. It occurs in some individuals when getting a shot or when seeing blood. Some know that they are about to faint due to symptoms beforehand such as feeling nauseated, weak, dizzy or hot. Upon waking up, they feel dizzy, confused or sick for a short time.

When is fainting an indication of a serious issue?

It is important to note that fainting might be an indication of a serious issue if:

  • It occurs in a short span of time
  • It arises during exercise or strenuous physical activity
  • There is chest pain
  • It occurs without warning or when the individual is already lying down
  • There is significant loss of blood which also includes internal bleeding
  • There is shortness of breath
  • There is a feeling that the heart is racing or erratically beating
  • It is accompanied by tingling or numbness on one side of the face or body


If the individual has a feeling that he/she is about to faint at certain times, it is best to:

  • Sit with the head positioned between the knees or lie down if feeling faint or have warning indications such as feeling weak, dizzy, warm or sick.
  • Stand up slowly
  • Provide more fluids to drink to prevent dehydration

A doctor should be seen if the individual has persistent dizziness or fainting episodes.

Quick Note / Disclaimer

The material posted on this page on fainting is for learning and educational purposes only. To learn to properly manage fainting, register for a first aid and CPR course with Victoria First Aid.

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