A broken bone — also referred to as a fracture — can involve any one, or all, of the bones in your arm:

  • humerus, upper arm bone reaching from the shoulder to the elbow
  • ulna, forearm bone reaching from the elbow to the smallest finger side of the wrist, running parallel to the other, shorter, thicker forearm bone — the radius
  • radius, forearm bone reaching from the elbow to the thumb side of the wrist, running parallel to the other, longer, thinner forearm bone — the ulna

If you think that you or someone you’re with has broken a bone in their arm, get medical attention as soon as possible. Prompt treatment for a fracture increases the probability of proper healing.

The first indication that you have broken a bone in your arm could be actually hearing the bone break with a snapping or cracking sound. Other symptoms include:

  • deformity, arm appears to be crooked
  • severe pain
  • pain that increases with movement
  • difficulty moving arm, especially from palm-up to palm-down or vice versa
  • swelling
  • bruising
  • arm or hand feels tingly or numb

If there are deep cuts that could be part of the injury — such as a broken bone coming through the skin — there is a risk of infection. The wound will need to be cleaned and treated by a medical professional to block infectious agents such as bacteria.

Most broken arms are caused by physical trauma including:

  • Falls. The most common cause of a broken arm is a fall onto an elbow or outstretched hand (trying to break the fall).
  • Sports injuries. All types of arm fractures can occur from direct blows during athletic competitions.
  • Severe trauma. Arm bones can be broken from direct trauma such as bicycle, motorcycle, or car accident.

Your doctor will start with a physical examination of the arm, looking for:

  • deformity
  • tenderness
  • swelling
  • blood vessel damage
  • nerve damage

After the physical exam, your doctor will most likely order an X-ray to see the exact location and extent of the break — or number of breaks — in the bone. Occasionally, your doctor will want more detailed images and order an MRI or CT scan.

Treating a broken arm typically follows four steps:

  1. Setting the bone. The bone fragments on each side of the break have to be correctly aligned so they can grow back together. The doctor might need to perform a reduction (moving the pieces back into proper position).
  2. Immobilization. Your broken arm bone must be restricted in terms of movement. Depending on the type of break, your doctor might recommend a splint, a brace, a cast, or a sling.
  3. Medication. Based on your needs, your doctor might recommend an over-the-counter (OTC) or prescription pain reliever to lower pain and reduce inflammation. If you have an open wound accompanying the fracture, your doctor may prescribe an antibiotic to prevent infection that could reach the bone.
  4. Therapy. You doctor might recommend physical therapy while your arm is still immobilized and, after the splint or cast is removed, will most likely suggest rehabilitation exercises to reestablish flexibility and muscle strength.

Sometimes surgery is necessary to properly stabilize and realign the break. In certain situations, your doctor may have to use fixation devices, such as plates and screws or rods, to keep the bones in the correct position during the healing process.

Although dependent on a number of variables from your age to the type and location of the fracture, in most cases, the cast will be on for four to six weeks and activities may be limited for two to three months after the cast is removed.

The outlook for most broken arms is positive, especially if treated early. However, there are some complications that might occur, such as:

  • Infection. If a part of your broken bone breaks through your skin, it can be exposed to infection. It’s critically important that you get immediate medical treatment for this type of break — known as an open or compound fracture.
  • Stiffness. Because of the immobilization necessary to heal an upper arm bone fracture, sometimes an uncomfortable limited range of motion of the shoulder or elbow occurs.
  • Uneven growth. If a child whose arm bones are still growing breaks an arm bone near the end of the growth plate (end of the bone), that bone may grow unevenly in relationship to other bones.
  • Arthritis. If your fracture extended into a joint, down the road (possibly many years) you may experience osteoarthritis in that joint.
  • Nerve or blood vessel damage. If you break your humerus (upper arm bone) into two or more pieces, the rough ends might injure nearby blood vessels (causing circulation problems) and nerves (causing numbness or weakness).

If you break a bone in your arm, get medical attention as soon as possible. The faster you get treatment, the more likely your arm will heal properly. Proper healing will likely include four to six weeks of immobilization in a splint, brace, cast, or sling, and three to four months of limited activity and physical therapy.