For severe bleeding, take these first-aid steps.
Call 911 or your local emergency number if the wound is deep or you're not sure how serious it is. Don't move the injured person except if needed to avoid further injury.
Before checking for the source of the wound, put on disposable gloves and other personal protective equipment if you have them.
Stop the bleeding. Cover the wound with sterile gauze or a clean cloth. Press on it firmly with the palm of your hand until bleeding stops. But don't press on an eye injury or embedded object. Don't press on a head wound if you suspect a skull fracture.
Wrap the wound with a thick bandage or clean cloth and tape. Lift the wound above heart level if possible.
Tourniquets: A tourniquet is effective in controlling life-threatening bleeding from a limb. If needed, apply a commercially made tourniquet if it's available and you're trained in how to use it. Don't use an improvised tourniquet, such as a scarf or a belt.
When emergency help arrives, tell them how long the tourniquet has been in place.
Keep the person still. If you're waiting for emergency help to arrive, try to keep the injured person from moving.
If you haven't called for emergency help, get the injured person to an emergency room as soon as possible.