Corns and calluses are thick, hardened layers of skin that develop when your skin tries to protect itself against friction and pressure. They most often develop on the feet and toes or hands and fingers. Corns and calluses can be unsightly.

If you're healthy, you need treatment for corns and calluses only if they cause discomfort. For most people, simply eliminating the source of friction or pressure makes corns and calluses disappear.

If you have diabetes or another condition that causes poor blood flow to your feet, you're at greater risk of complications from corns and calluses. Seek your doctor's advice on proper care for corns and calluses if you have such a condition.

You may have a corn or a callus if you notice:

• A thick, rough area of skin
• A hardened, raised bump
• Tenderness or pain under your skin
• Flaky, dry or waxy skin

Corns and calluses are not the same thing.

• Corns are smaller than calluses and have a hard center surrounded by inflamed skin. Corns tend to develop on parts of your feet that don't bear weight, such as the tops and sides of your toes and even between your toes. They can also be found in weight-bearing areas. Corns can be painful when pressed.
• Calluses are rarely painful. They usually develop on the soles of your feet, especially under the heels or balls, on your palms, or on your knees. Calluses vary in size and shape and are often larger than corns.

When to see a doctor

If a corn or callus becomes very painful or inflamed, see your doctor. If you have diabetes or poor blood flow, call your doctor before self-treating a corn or callus because even a minor injury to your foot can lead to an infected open sore (ulcer).

Pressure and friction from repetitive actions cause corns and calluses to develop and grow. Some sources of this pressure and friction include:

• Wearing ill-fitting shoes. Tight shoes and high heels can compress areas of your feet. When footwear is too loose, your foot may repeatedly slide and rub against the shoe. Your foot may also rub against a seam or stitch inside the shoe.
• Skipping socks. Wearing shoes and sandals without socks can cause friction on your feet. Socks that don't fit properly also can be a problem.
• Playing instruments or using hand tools. Calluses on your hands may result from the repeated pressure of playing instruments, using hand tools or even writing.

These factors may increase your risk of corns and calluses:

• Bunions. A bunion is an abnormal, bony bump that forms on the joint at the base of your big toe.
• Hammertoe. A hammertoe is a deformity in which your toe curls like a claw.
• Other foot deformities. Certain conditions, such as a bone spur, can cause constant rubbing inside your shoe.
• Not protecting your hands. Using hand tools without wearing gloves exposes your skin to excessive friction.

These approaches may help you prevent corns and calluses:

• Wear shoes that give your toes plenty of room. If you can't wiggle your toes, your shoes are too tight. Have a shoe shop stretch your shoes at any point that rubs or pinches.
• Use protective coverings. Wear felt pads, nonmedicated corn pads or bandages over areas that rub against your footwear. You can also try toe separators or some lamb's wool between your toes.
• Wear padded gloves when using hand tools. Or try padding your tool handles with cloth tape or covers.

Your doctor will examine your feet and rule out other causes of thickened skin, such as warts and cysts. He or she may recommend an X-ray if a physical abnormality is causing the corn or callus.

Treatment for corns and calluses usually involves avoiding the repetitive actions that caused them to develop. You can help resolve them by wearing properly fitting shoes, using protective pads and taking other self-care measures.

If a corn or callus persists or becomes painful despite your self-care efforts, medical treatments can provide relief:

• Trimming away excess skin. Your doctor can pare down thickened skin or trim a large corn with a scalpel, usually during an office visit. Don't try this yourself because it could lead to an infection.
• Callus-removing medication. Your doctor may also apply a patch containing 40 percent salicylic acid (Clear Away, MediPlast,others). Such patches are available without a prescription. Your doctor will let you know how often you need to replace this patch. He or she may recommend that you use a pumice stone, nail file or emery board to smooth away dead skin before applying a new patch. You can also get a prescription for salicylic acid in gel form to apply on larger areas.
• Shoe inserts. If you have an underlying foot deformity, your doctor may prescribe custom-made padded shoe inserts (orthotics) to prevent recurring corns or calluses.
• Surgery. In rare instances, your doctor may recommend surgery to correct the alignment of a bone causing friction.

If you have diabetes or another condition that causes poor blood flow, consult your doctor before treating a corn and callus on your own.

If you have no underlying health problems, try these suggestions to help clear up a corn or callus:

• Use over-the-counter pads. Apply a pad to protect the area where a corn or callus developed. Be careful using over-the-counter (nonprescription) liquid corn removers or medicated corn pads. These contain salicylic acid, which can irritate healthy skin and lead to infection, especially in people with diabetes or other conditions that cause poor blood flow.
• Soak your hands or feet. Soaking your hands or feet in warm, soapy water softens corns and calluses. This can make it easier to remove the thickened skin.
• Thin thickened skin. During or after bathing, rub a corn or callus with a pumice stone, nail file, emery board or washcloth to help remove a layer of toughened skin. Don't use a sharp object to trim the skin. Don't use a pumice stone if you have diabetes.
• Moisturize your skin. Apply moisturizer to your hands and feet to help keep the skin soft.
• Wear comfortable shoes and socks. Stick to well-fitting, cushioned shoes and socks until your corn or callus disappears.