A cast is a hard bandage that keeps part of the body from moving so it can heal.
Why Do People Need Casts?
People get casts after a broken
bone, some surgeries, and other injuries.
What Are the Different Kinds of Casts?
Most casts are made of fiberglass. Fiberglass is a kind of plastic that is moldable
and dries hard. Some fiberglass casts are waterproof.
Less often, casts are made of plaster of paris. This white powder is mixed with
water into a paste. The paste hardens when it's dried.
Is There a Waterproof Cast?
Yes, there is a cast that can be worn in showers and pools. A waterproof cast is
a regular fiberglass cast with a different type of liner. Doctors use waterproof casts
only for some kinds of broken bones.
How Are Casts Put On?
A health care provider such as an
, emergency room doctor,
, orthopedic technician, or
puts on the cast.
To put on the cast, the health care provider:
wraps a liner of soft material around the injured area (for a waterproof cast,
a different liner is used)
wets the cast material with water
wraps the cast material around the first layer
waits until the outer layer dries to a hard, protective covering
A fiberglass cast gets warm as it hardens. It cools in about 15 minutes.
How Can I Prevent Problems With a Cast?
If the cast is not waterproof, keep the cast and liner dry. A wet cast or liner
can lead to a skin rash or infection.
Don't pull out the lining or break off any parts of the cast.
If there is a sharp edge, put tape or moleskin on the edge of the cast.
If the cast is itchy:
Tap on the outside of the cast.
Use a hair dryer on the cool or fan-only setting to blow air in at the edges of
Never use an object to scratch under the cast. Scratching can lead to an infection
or sores. Don't apply lotion or powder inside the cast.
How Should I Care for the Cast?
If the Cast Is Waterproof:
Flush the cast and liner with clean water to remove soap after showers.
Dry the waterproof cast with a hair dryer on the cool or fan-only setting after
showering or swimming.
If the Cast Is Not Waterproof:
Casts that don't have a special waterproof liner must be kept dry. It is better
to take a bath than a shower because it is easier to keep the cast dry in a bath.
To keep the cast dry while bathing:
Before the bath, cover the cast with two plastic bags. First, put one bag on and
seal the top with a rubber band. Then, put the second bag on and seal it with another
Some people use a waterproof plastic cast protector instead of plastic bags. You
can buy this at a drugstore.
Keep the cast completely out of the water by propping it up on the side of the
If the cast or liner gets splashed, gently blow air into it from a hair dryer on
the cool or fan-only setting. If some of the cast or liner goes under water or gets
very wet, call your doctor.
When Should I Call the Doctor?
Call your doctor if:
The cast feels too tight.
The cast was comfortable but is now uncomfortable.
You have new pain or pain that gets worse.
Your fingers or toes get more swollen, change colors, hurt, or feel numb.
Something is stuck in the cast, like a piece of food.
A bad smell or any kind of fluid is coming from the cast.
A non-waterproof cast or liner gets wet.
How Are Casts Taken Off?
Health care providers take off casts with a small electrical saw. The saw cuts
through the cast material but stops before it touches the skin.
When the cast is off,
the skin will probably look pale, dry, or flaky. The hair will look darker and the
muscles will look smaller. This is normal and goes away within a few weeks.
Take care of your cast so it stays in good condition and does not lead to irritation.
Within a few months, you can get back to all the activities you enjoyed before the