Is That a Callus, or a Pressure Sore?
They can look similar, but the difference matters enormously. Here's how to tell them apart and what to do about each.
At ASG Foot & Ankle Specialists, one of the most common (and most dangerous) situations we encounter is a patient who has been treating what they thought was a callus, only to discover a pressure sore hiding underneath. This is especially common in diabetic patients, where neuropathy masks pain and allows wounds to develop undetected.
Knowing the difference between a callus and a pressure sore can genuinely save your foot, and in the case of a deep infection that spreads, your life.
Medically reviewed by Dr. Timothy Horak and Julia Shauger, board-certified podiatric specialists serving Homewood, South Chicago Heights & Mokena. Last reviewed July 2026.
Callus vs. Pressure Sore: Key Differences
Callus (Hyperkeratosis)
- Appearance: Thick, hardened, yellowish or grayish skin
- Texture: Firm, dry, rough surface
- Pain: Usually painless; may cause dull aching
- Location: Pressure points such as the ball of the foot, heel, and sides of the toes
- Cause: Repeated friction or pressure on skin
- Skin integrity: Skin surface intact
Pressure Sore (Pressure Ulcer)
- Appearance: Discolored skin, blister, open wound, or dark area
- Texture: May feel soft, boggy, or spongy in center
- Pain: Painful OR painless (diabetics may feel nothing)
- Location: Same pressure points, but also bony prominences
- Cause: Sustained pressure cutting off blood supply to tissue
- Skin integrity: Tissue breakdown, so the skin may be broken or dying
The Hidden Danger: Pressure Sores Under Calluses
This is the scenario that keeps podiatrists up at night: a thick callus forms over a pressure point, and beneath it, a pressure ulcer quietly develops. The callus acts as a mask. It hides the wound and, in diabetic patients with neuropathy, eliminates the pain signal that would normally alert you something is wrong.
By the time the callus is removed, the underlying ulcer can be deep, infected, and potentially involving bone (osteomyelitis). This is one of the leading pathways to diabetic foot amputation.
Warning signs a callus may be hiding something worse:
- • Callus has a dark center or dark spot underneath
- • Callus feels soft or spongy in the middle
- • Drainage or moisture under the callus
- • Callus is growing rapidly
- • Surrounding skin is red, warm, or swollen
- • You have diabetes, since any callus needs professional evaluation
Pressure Sore Stages on the Foot
Stage 1
Intact skin with non-blanchable redness. The area may feel warmer, firmer, or softer than surrounding skin. Painful in patients with normal sensation.
Stage 2
Partial thickness skin loss, seen as a shallow open wound with a pink/red wound bed, or an intact or ruptured blister. No slough (dead tissue) present.
Stage 3
Full thickness skin loss. Subcutaneous fat may be visible. Slough may be present. Depth varies by location, and it can be quite deep on the heel or ball of the foot.
Stage 4
Full thickness tissue loss with exposed bone, tendon, or muscle. Slough or eschar (dead tissue) often present. Osteomyelitis (bone infection) is possible. Requires urgent specialist care.
Treatment: Callus vs. Pressure Sore
Treating a Callus
- Professional debridement by a podiatrist (safest, especially for diabetics)
- Pumice stone or foot file after soaking (non-diabetics only)
- Moisturizing with urea-based creams
- Custom orthotics to redistribute pressure
- Better-fitting footwear
Treating a Pressure Sore
- Offloading, which means removing all pressure from the wound
- Wound debridement (remove dead tissue)
- Appropriate moist wound dressings
- Antibiotics if infected
- Advanced therapies for non-healing wounds
Had a corn or callus removed?
See what recovery actually looks like and how to keep it from coming back.
Corn & Callus Removal Recovery →Is the callus painful?
Callus tissue has no nerve endings, so if it hurts, something underneath it is causing the pain.
Why Your Callus Hurts →Have diabetes?
Diabetic patients should never self-treat calluses. Learn about our specialized diabetic wound care program.
Diabetic Wound Care →Could it be a wart?
Plantar warts build a callus-like cap over themselves and are confused with calluses constantly.
Plantar Wart Removal Recovery →Wound not healing?
Learn the top tips for faster foot wound healing from our expert podiatrists.
Wound Healing Tips →After a toe amputation?
Pressure redistributes onto areas that never carried it before, and on a numb foot that happens silently.
Toe Amputation Recovery →Frequently Asked Questions
How do I know if I have a callus or a pressure sore?
A callus is a thickened, hardened area of skin that is usually painless and yellowish. A pressure sore (pressure ulcer) involves tissue breakdown, so it may look like a blister, open wound, or area of discolored skin that doesn't blanch when pressed. Pressure sores are often painful (or painless in diabetics due to neuropathy) and can have a soft, boggy center. If you're unsure, see a podiatrist, because a callus hiding a pressure sore underneath is a common and dangerous situation.
Can a callus turn into a pressure sore?
Yes, and this is one of the most dangerous foot problems we see, especially in diabetic patients. A thick callus can hide a pressure ulcer developing underneath. The callus masks the pain, so patients don't realize there's a wound forming beneath the hardened skin. By the time the callus is removed, the underlying ulcer can be deep and infected. Regular podiatry visits for callus debridement are essential for diabetic patients.
How are pressure sores on the foot treated?
Pressure sore treatment involves removing pressure from the area (offloading), wound debridement, appropriate wound dressings, infection management if needed, and addressing underlying causes like poor circulation or ill-fitting footwear. Diabetic patients with pressure sores need specialized wound care and close monitoring to prevent serious complications.
Specialized Wound Care at ASG Foot & Ankle
Our board-certified podiatrists treat slow-healing wounds, diabetic foot ulcers, and post-surgical wounds at our three clinics in Homewood, South Chicago Heights, and Mokena.
Feet burning at night, or going numb?
The burning is what people ask about. The numbness is the symptom that costs feet.
Diabetic Neuropathy in the Feet →Still walking on the ulcer?
Pressure is what keeps a foot ulcer open. Why the device you cannot remove beats the boot you can.
Offloading a Foot Ulcer →A pre-ulcerative callus qualifies you for covered footwear. Diabetic Shoes and Medicare →
See a Podiatrist Near You
ASG Foot & Ankle has offices in Homewood, South Chicago Heights and Mokena. Our board-certified podiatrists accept most insurance. Find the office closest to you:
Not Sure What You're Dealing With? Let Us Take a Look.
Our board-certified podiatrists can quickly determine whether you have a callus, a pressure sore, or something more serious, and get you on the right treatment plan. Three locations in the South Chicago suburbs.