A Sore That Won't Heal: When to Worry and What to Do

What does "won't heal" actually mean?

Normal skin heals a small cut or abrasion within one to two weeks, progressing through well-defined phases: initial clotting, inflammation, new tissue formation, and remodeling 1Ref 1Bowers S, Franco E (2020).Chronic Wounds: Evaluation and Management.Definition of chronic wound (failure to heal within 3 months); four main types of chronic wounds (venous, arterial, diabetic, pressure); evaluation framework including vascular assessment and biopsy for atypical wounds; the TIME wound management principle. A sore that is still open, weeping, bleeding, scabbing over, or growing after three to four weeks has crossed a threshold that warrants professional evaluation. At that point the wound has stalled — the body is attempting to heal but something is interfering — and that something could range from poor circulation to an underlying skin cancer.

Clinically, a wound that fails to progress through the normal orderly sequence of repair within this timeframe is considered a chronic wound requiring evaluation beyond simple first-aid 1Ref 1Bowers S, Franco E (2020).Chronic Wounds: Evaluation and Management.Definition of chronic wound (failure to heal within 3 months); four main types of chronic wounds (venous, arterial, diabetic, pressure); evaluation framework including vascular assessment and biopsy for atypical wounds; the TIME wound management principle. Location matters: a sore on the face, scalp, or ear in an older adult with sun-exposure history has a different differential than a leg sore in someone with diabetes.

Why is skin cancer the reason not to wait?

Basal cell carcinoma (BCC) is the most common skin cancer in people with lighter skin, with a lifetime risk estimated at roughly 30% 2Ref 2Seidl-Philipp M, Frischhut N, Höllweger N, Schmuth M, Nguyen VA (2021).Known and new facts on basal cell carcinoma.BCC as the most common malignant tumor in light-skinned individuals with lifetime risk ~30%; UV exposure, male sex, light skin type, and advanced age as primary risk factors. One classic presentation is a sore that bleeds easily, scabs over, appears to heal partially, then breaks down again — in a repeating cycle, sometimes for months 3Ref 3American Academy of Dermatology (2024).Skin cancer types: Basal cell carcinoma diagnosis and treatment.Skin biopsy as the confirmatory diagnostic step for BCC; treatment options including surgical excision, Mohs micrographic surgery, topical medications, and other modalities. It often looks like a pink or pearly bump, a flat scar-like area, or a pink patch on sun-exposed skin such as the face, nose, ears, scalp, or chest. Squamous cell carcinoma can appear similarly, or as a firm, rough, crusted growth.

Both are highly treatable when caught early — most are resolved with an in-office procedure 3Ref 3American Academy of Dermatology (2024).Skin cancer types: Basal cell carcinoma diagnosis and treatment.Skin biopsy as the confirmatory diagnostic step for BCC; treatment options including surgical excision, Mohs micrographic surgery, topical medications, and other modalities. Waiting allows them to grow larger and invade nearby tissue, requiring more extensive treatment. This is why clinicians prioritize evaluating non-healing sores: early detection changes outcomes meaningfully.

What other conditions cause a sore that won't close?

Non-healing sores are not always cancer. The most common other causes:

• Poor circulation from diabetes or peripheral vascular disease — starves the skin of the oxygen required for healing; a leading cause of leg and foot ulcers, particularly on the ankle and sole. Diabetic foot ulcers are the leading cause of lower-extremity amputation 1Ref 1Bowers S, Franco E (2020).Chronic Wounds: Evaluation and Management.Definition of chronic wound (failure to heal within 3 months); four main types of chronic wounds (venous, arterial, diabetic, pressure); evaluation framework including vascular assessment and biopsy for atypical wounds; the TIME wound management principle.
• Venous insufficiency — pooled blood and tissue swelling in the lower leg impairs healing; venous ulcers affect 1–3% of older adults and are the most common type of chronic lower-leg wound 1Ref 1Bowers S, Franco E (2020).Chronic Wounds: Evaluation and Management.Definition of chronic wound (failure to heal within 3 months); four main types of chronic wounds (venous, arterial, diabetic, pressure); evaluation framework including vascular assessment and biopsy for atypical wounds; the TIME wound management principle.
• Chronic mechanical irritation or an infected wound — a cut, bite, or scratch that keeps getting re-injured or infected can stall wound closure.
• Inflammatory skin conditions — conditions such as pyoderma gangrenosum produce ulcers that appear treatment-resistant and require specialist care.

Location is a useful clue: lower-leg sores in someone with diabetes or circulation problems are more likely vascular in origin; a sore on the face or scalp in an older adult with sun exposure history raises the suspicion for skin cancer 1Ref 1Bowers S, Franco E (2020).Chronic Wounds: Evaluation and Management.Definition of chronic wound (failure to heal within 3 months); four main types of chronic wounds (venous, arterial, diabetic, pressure); evaluation framework including vascular assessment and biopsy for atypical wounds; the TIME wound management principle.

What should you do now?

Schedule a visit within one to two weeks. In the meantime, keep the area clean and lightly covered. Avoid picking at scabs. Take a clear photo today in good natural lighting — both to document the current appearance and to compare at your appointment.

Bring photographs over time if you have them, a note of when you first noticed the sore, any changes in size or behavior, and a full medication list (especially blood thinners and immunosuppressants).

If the sore starts rapidly expanding, becomes very painful, smells foul, or if you develop a fever, seek same-day care — these signs can indicate a serious skin infection (cellulitis or necrotizing infection) that requires prompt treatment 1Ref 1Bowers S, Franco E (2020).Chronic Wounds: Evaluation and Management.Definition of chronic wound (failure to heal within 3 months); four main types of chronic wounds (venous, arterial, diabetic, pressure); evaluation framework including vascular assessment and biopsy for atypical wounds; the TIME wound management principle.

What might a clinician do at the visit?

A trained clinician will examine the sore and surrounding skin, often with dermoscopy — a hand-held polarized-light device that reveals vascular patterns and structural features invisible to the naked eye. If the appearance is concerning for skin cancer or the diagnosis is unclear, a skin biopsy — a small tissue sample sent to a pathologist — is the definitive diagnostic step 3Ref 3American Academy of Dermatology (2024).Skin cancer types: Basal cell carcinoma diagnosis and treatment.Skin biopsy as the confirmatory diagnostic step for BCC; treatment options including surgical excision, Mohs micrographic surgery, topical medications, and other modalities. This is a minor procedure done under local anesthetic in the office.

If the sore suggests poor circulation, a vascular assessment such as an ankle-brachial index or Doppler ultrasound of the leg vessels may be arranged. Tissue culture guides antibiotic selection when infection is playing a role. For atypical wounds that do not respond to initial treatment, biopsy is indicated regardless of initial appearance 1Ref 1Bowers S, Franco E (2020).Chronic Wounds: Evaluation and Management.Definition of chronic wound (failure to heal within 3 months); four main types of chronic wounds (venous, arterial, diabetic, pressure); evaluation framework including vascular assessment and biopsy for atypical wounds; the TIME wound management principle.

How are different types of non-healing sores treated?

Treatment depends entirely on the underlying cause identified after evaluation:

• Skin cancer (BCC or SCC): Surgical excision, Mohs micrographic surgery for higher-risk locations (face, ears, nose), electrodesiccation and curettage, or topical medications for superficial lesions 3Ref 3American Academy of Dermatology (2024).Skin cancer types: Basal cell carcinoma diagnosis and treatment.Skin biopsy as the confirmatory diagnostic step for BCC; treatment options including surgical excision, Mohs micrographic surgery, topical medications, and other modalities.
• Venous ulcers: Compression therapy to reduce venous hypertension, elevation, and exercise. Wound dressings maintain moisture balance 1Ref 1Bowers S, Franco E (2020).Chronic Wounds: Evaluation and Management.Definition of chronic wound (failure to heal within 3 months); four main types of chronic wounds (venous, arterial, diabetic, pressure); evaluation framework including vascular assessment and biopsy for atypical wounds; the TIME wound management principle.
• Diabetic or arterial ulcers: Optimizing blood sugar, vascular assessment, offloading pressure from the foot. Vascular intervention may restore blood flow and enable healing 1Ref 1Bowers S, Franco E (2020).Chronic Wounds: Evaluation and Management.Definition of chronic wound (failure to heal within 3 months); four main types of chronic wounds (venous, arterial, diabetic, pressure); evaluation framework including vascular assessment and biopsy for atypical wounds; the TIME wound management principle.
• Infected wounds: Appropriate antibiotic therapy guided by culture results.

For any non-healing sore, the general principle of wound management — removing non-viable tissue, controlling infection, maintaining moisture, and supporting wound edges — applies while the underlying cause is addressed 1Ref 1Bowers S, Franco E (2020).Chronic Wounds: Evaluation and Management.Definition of chronic wound (failure to heal within 3 months); four main types of chronic wounds (venous, arterial, diabetic, pressure); evaluation framework including vascular assessment and biopsy for atypical wounds; the TIME wound management principle.