A snap or cracking sound might be your first indication you've broken an arm. Signs and symptoms include:

• Severe pain, which might increase with movement
• Swelling
• Bruising
• Deformity, such as a bent arm or wrist
• Inability to turn your arm from palm up to palm down or vice versa

Common causes for a broken arm include:

• Falls. Falling onto an outstretched hand or elbow is the most common cause of a broken arm.
• Sports injuries. Direct blows and injuries on the field or court cause all types of arm fractures.
• Significant trauma. Any of your arm bones can break during a car accident, bike accident or other direct trauma.
• Child abuse. In children, a broken arm might be the result of child abuse.

Certain medical conditions or physical activities can increase the risk of a broken arm.

Certain sports

Any sport that involves physical contact or increases your risk of falling — including football, soccer, gymnastics, skiing and skateboarding — also increases the risk of a broken arm.

Bone abnormalities

Conditions that weaken bones, such as osteoporosis and bone tumors, increase your risk of a broken arm. This type of break is known as a pathological fracture.

The prognosis for most arm fractures is very good if treated early. But complications can include:

• Uneven growth. Because a child's arm bones are still growing, a fracture in the area where growth occurs near each end of a long bone (growth plate) can interfere with that bone's growth.
• Osteoarthritis. Fractures that extend into a joint can cause arthritis there years later.
• Stiffness. The immobilization required to heal a fracture in the upper arm bone can sometimes result in painfully limited range of motion of the elbow or shoulder.
• Bone infection. If a part of your broken bone protrudes through your skin, it can be exposed to germs that can cause infection. Prompt treatment of this type of fracture is critical.
• Nerve or blood vessel injury. If the upper arm bone (humerus) fractures into two or more pieces, the jagged ends can injure nearby nerves and blood vessels. Seek immediate medical attention if you notice numbness or circulation problems.
• Compartment syndrome. Excessive swelling of the injured arm can cut off the blood supply to part of the arm, causing pain and numbness. Typically occurring 24 to 48 hours after the injury, compartment syndrome is a medical emergency that requires surgery.