A loud cracking or snap is usually the first sign your arm is broken. It also may appear deformed, swollen, bruised or bleed.
Other symptoms include extreme pain, increased pain with movement and loss of normal use of the arm.
To slow bleeding and reduce swelling, raise the injured arm above the level of your heart. If a broken bone sticks out from the skin (open fracture), do not try to push it back in. Use a clean, dry cloth or bandage to cover it until medical help arrives.
It is important that you not try to use the broken arm. Moving a broken arm would also cause more damage to blood vessels, nerves and other tissues. To keep the broken area from moving, make a temporary splint, by taping a ruler or other supportive device to the arm. Even though a sling can be made from a scarf supported from the neck, the patient should go to the Emergency Room right away.