You can make a functional arm sling at home using a square piece of fabric roughly 40 to 42 inches on each side, folded diagonally into a triangle. A bedsheet, pillowcase, large towel, or even a long-sleeved shirt will work if you don’t have a proper bandage. The goal is to hold your injured arm against your chest with the elbow bent at a right angle and the hand positioned slightly higher than the elbow to reduce swelling.
What You Need
The standard triangular bandage sold by the Red Cross measures 42 by 42 by 59 inches, but you don’t need to match those dimensions exactly. Any piece of fabric large enough to wrap from your hand to your elbow and tie behind your neck will do. Cut a square roughly 36 to 42 inches per side from a bedsheet, tablecloth, or large towel, then fold it corner to corner to form a triangle. If you’re using a pillowcase, cut along one long seam and the bottom seam to open it flat, then fold diagonally.
Scissors, a safety pin or two, and a soft washcloth for padding under the neck strap are helpful to have nearby before you start.
Step-by-Step Triangular Sling
Bend the injured arm at the elbow so the forearm is roughly horizontal across your chest. The elbow should form a right angle, close to 90 degrees.
Drape the triangular fabric so one point hangs down past your elbow on the injured side, the long edge runs vertically along your body, and the opposite point reaches over your uninjured shoulder. Slide the hanging point under your forearm and elbow, then bring it up and over the shoulder on the injured side. Tie the two upper points together at the side of your neck, never directly over the spine. A square knot (right over left, then left over right) holds well and unties easily later.
Fold or pin the loose fabric at the elbow so the sling cups snugly around the joint with no slack. Your fingertips should remain visible and exposed so you can check their color and sensation. Adjust the knot height until your hand rests slightly above elbow level. The finished sling should hold your arm comfortably against your chest without sagging or pulling your neck to one side.
The T-Shirt Method
If you don’t have time or materials to cut fabric, a long-sleeved shirt, sweatshirt, or jacket works as a quick improvised sling. Tie the two sleeves together behind your neck, creating a loop of fabric in front of your chest. Slip your injured arm into that loop so the body of the shirt cradles your forearm. Adjust the knot so your elbow stays near 90 degrees and your hand sits above elbow height. This method requires no cutting and takes under a minute.
Padding the Neck Strap
A thin fabric strap pressing into the side of your neck gets painful fast, especially if you’ll be wearing the sling for more than a few minutes. Fold a soft washcloth, hand towel, or piece of fleece and slip it under the strap where it crosses your neck and shoulder. This distributes pressure over a wider area and prevents the strap from digging into skin or compressing the nerves that run along the side of your neck.
Check the fit by sliding two or three fingers between the strap and your body. If you can’t fit them, the sling is too tight. If your hand slides freely through the gap, it’s too loose and won’t support the arm properly.
Adjusting for Wrist vs. Shoulder Injuries
The position of your hand inside the sling should change depending on where the injury is. For a shoulder injury or upper arm fracture, a standard broad-arm sling with the hand just slightly above the elbow works well. The forearm stays roughly horizontal, and the sling supports the weight of the entire arm so the shoulder doesn’t have to.
For injuries below the elbow (fingers, hand, wrist, or forearm), you want a high-arm sling. Tie the knot higher or shorten the fabric so your hand sits well above elbow level, closer to the opposite shoulder. This elevated position helps control swelling in the hand and fingers. If you have a cast or splint on the wrist or forearm, make sure the sling is wide enough to cradle the full length of it without the edges pressing into your skin.
Checking Circulation
Once the sling is in place, keep an eye on your fingertips. They should stay warm and their normal color. Press a fingernail for a second and release: the pink color should return within two seconds. Signs of restricted blood flow include fingers that turn pale, bluish, or feel cold or numb. Tingling or a “pins and needles” sensation also suggests the sling is too tight or positioned poorly. If you notice any of these changes, loosen the knot, readjust the fabric, and recheck.
It helps to wiggle your fingers gently every 15 to 20 minutes. This keeps blood moving and gives you an easy way to notice if sensation or movement is declining.
When a Homemade Sling Isn’t Enough
A homemade sling is a temporary measure. It stabilizes the arm and reduces pain during transport or while you arrange professional care, but it doesn’t treat the underlying injury. Certain signs mean you should get to an emergency room rather than managing at home:
- Visible deformity. The arm, shoulder, or wrist sits at an unusual angle, or bone is visible through the skin.
- A snapping or cracking sound at the time of injury. This often signals a fracture.
- Severe swelling that develops rapidly, especially with intense pain that doesn’t ease when the arm is supported.
- Inability to move the arm normally, including trouble rotating the forearm palm-up to palm-down.
- Complete numbness or loss of sensation in the hand or fingers that doesn’t improve after loosening the sling.
A sling made from a bedsheet can be just as effective as a store-bought bandage for short-term support. The key details that matter most are keeping the elbow at 90 degrees, the hand above the elbow, the knot off the spine, and the fingertips visible so you can monitor circulation until you can get proper medical evaluation.