Lets imagine a scenario, a man is riding his bike to work and a car comes round the corner and doesn't see him. The man is knocked off his bike and hits his head on the pavement. You are walking on the pavement and see the whole thing happen but now what?

DRSABCD is your primary survey and one of the first things you'll learn in a first aid lesson.
Here it is broken down:

D = Danger
When approaching an incident check for any dangers to yourself, the casualty and any bystanders

R = Response
Try to get a response from the casualty. Are they alert? Do they respond to you verbally or physically?

S = Shout
Shout for help to any bystanders around you.

A = Airways
Check the casualties airways to make sure they are clear from any blockages.

B = Breathing
Check the casualty is breathing

C = CPR/Circulation
If the casualty is not breathing call an ambulance and start CPR. If they are breathing check for other signs of injuries.

D = Defibrillation
If casualty is not breathing and there is an AED machine available use it on the casualty until the ambulance arrive.

So if you are first on the scene of an accident always remember DRSABCD.

You can learn more about this on our open first aid courses.