Callus

How calluses form

When skin is rubbed or pressed over and over, the outer layer (the stratum corneum) thickens to protect the tissue beneath. This build-up of keratin is called hyperkeratosis. Calluses form slowly, over weeks to months, and tend to be wide and flat with no sharp edges.

Corn vs callus

Callus vs plantar wart

A plantar wart can look like a callus. Warts interrupt the skin lines, have tiny black dots (clotted blood vessels) and hurt more when squeezed side to side. Calluses keep the skin lines running through them and hurt more with direct pressure.

Causes

On the feet

• shoes that are too tight, loose or high-heeled
• walking barefoot, or wearing shoes without socks
• foot deformities such as bunions, hammer toes, high arches or flat feet that shift weight onto certain areas
• a dropped forefoot or metatarsalgia, causing calluses under the ball of the foot
• running, dancing and long periods of standing
• older age, as the fat pads under the feet thin

On the hands

• manual work and tools
• gym equipment, rowing, climbing and gymnastics
• guitar and string instruments, causing fingertip calluses
• writing, causing a "writer's bump" on the middle finger

Less common causes

Inherited conditions (palmoplantar keratoderma) cause thick skin on the palms and soles without friction. Some medical conditions and medicines can also thicken skin.

Diagnosis

Calluses are diagnosed by examination. A podiatrist may watch you walk, look at your shoes and check for foot deformities. X-rays show bony prominences if surgery is being considered.

Treatment

At home

1. Remove the cause: wear shoes with enough width and depth, low heels and cushioned soles. Wear socks.
2. Soak the area in warm water for 5 to 10 minutes to soften the skin.
3. File gently with a pumice stone or foot file, a little at a time, after soaking. Stop before the skin becomes tender or pink.
4. Moisturize daily with a cream containing urea (10% to 25%), salicylic acid or ammonium lactate to soften thick skin.
5. Pad and protect: use non-medicated cushions, gel pads or gloves for work and sport.
6. Insoles or orthotics redistribute pressure if your foot shape is the cause.

Professional treatment

• Debridement: a podiatrist painlessly shaves off thick skin with a scalpel.
• Custom orthotics to offload pressure points.
• Surgery to correct a bony deformity, such as a bunion or hammer toe, if calluses keep returning and cause pain.

Calluses and diabetes

In people with diabetes and nerve damage, calluses are a warning sign. Pressure under a thick callus can cause bleeding and breakdown of the skin beneath, leading to a diabetic foot ulcer that may go unnoticed. Check your feet daily, never self-treat calluses, and see a podiatrist regularly for safe removal.

Frequently asked questions

What is the difference between a corn and a callus?

A callus is a broad, flat area of thickened skin on weight-bearing areas such as the sole or palm, and is usually painless. A corn is smaller and deeper, with a hard central core, usually on or between the toes, and is often painful when pressed.

How do you get rid of calluses permanently?

Calluses go away only when the pressure or friction causing them stops. Wear well-fitting, cushioned shoes, use padding or orthotics, and soak, file and moisturize regularly. If a foot deformity is the cause, correcting it may be needed.

Is it okay to cut off a callus?

No. Cutting a callus at home risks cuts, bleeding and infection, especially on the feet. Soften it by soaking and gently file it with a pumice stone instead. A podiatrist can safely trim very thick calluses.

Are calluses on hands good?

Calluses protect the hands of people who do manual work, play string instruments or lift weights. They are only a problem if they crack, tear, or become painful. Keeping them moisturized and filed smooth helps prevent painful splits.