Most of us will have experienced a faint at some point in our lives, but what exactly causes this phenomenon?

What is a faint and why does it happen?

A faint is a brief and sudden loss of consciousness, normally due to a reduction in the blood flow to the brain. Normally, a faint results in a person falling to the floor.

The brain requires a constant supply of Oxygen and nutrients, this supply is provided by the blood.

There are numerous things that can interrupt this supply. For example, blood tends to pool in the legs during periods of inactivity (e.g: standing or sitting for long periods of time).

If you suddenly stand up, the heart has to work harder to pump this blood upwards against gravity. This can cause a “head rush” in some people, with a feeling of dizziness.

However in other people, this interruption in the blood supply to the brain causes them to loose consciousness – a faint.

Generally once a person has fainted and fallen to the floor, they regain consciousness very quickly. This is because when lying down, the heart finds it easier to pump blood to the brain as it isn’t working against gravity.

There are some tell-tale signs that someone is going to faint. They may go very pale/white, and look unsteady on their feet. Also they may complain of feeling ‘light headed’ or ‘funny’.

First aid treatment for a faint

If someone complains of feeling faint you should sit them down on the floor if possible until they feel better. This is to prevent any injuries occurring if they do collapse. 

If someone has fainted, you should:

> Raise their legs to improve the blood supply to the brain.

> If they’ve fallen, check for any injuries such as fractures or head injuries.

> Once they recover, help them sit up gradually. Don’t let the casualty stand up straight away as they may just faint again!

If they casualty does not wake up, you should open their airway by tilting their head backwards and check to see if they’re breathing. If they are, roll them onto their side and call an ambulance.

If the casualty recovers fully and hasn’t suffered any injuries, there is no need to call an ambulance. If they are not sure what caused the faint, or haven’t fainting before then it is advisable for them to seek medical attention. Occasionally, a faint can be the sign of a more serious underlying medical condition.

If someone is fainting on a regular without any known cause, they should be encouraged to seek urgent medical advice.