What causes a skin sore that does not heal?

A wound can remain open when the skin is repeatedly rubbed, scratched, or exposed to pressure. Bacteria or other infection can delay repair, while reduced blood flow, swelling, diabetes, smoking, or poor nutrition may limit oxygen and building materials reaching the area. A rough patch called actinic keratosis can sometimes develop after long-term sun exposure. Basal cell carcinoma and squamous cell skin cancer can also appear as a sore, crust, or scab that fails to settle. A non-healing sore does not by itself establish cancer; examination is needed to distinguish these possibilities.

Gently rinse the area, pat it dry, and cover it with a clean dressing if clothing or movement causes friction. Do not pick the scab or apply strong antiseptics, steroid creams, or unprescribed antibiotics. Arrange a clinical assessment if the sore persists, keeps returning, bleeds, changes, or forms a firm edge. Take a dated photograph and note any pain, discharge, growth, or changes in colour to discuss at the visit.

Seek prompt medical care for spreading redness, warmth, increasing swelling, pus, fever, severe pain, numbness, or red streaks. A sore on the face, ear, hand, or genital area deserves careful assessment because these sites can be easily irritated and may affect function. Seek urgent help for heavy bleeding that does not stop with firm pressure, or if you feel faint or unwell.

Could pressure, infection, circulation, or a skin growth be delaying healing? Does the area need a swab, blood test, or biopsy? Which dressing and cleansing routine suits its location? What changes should prompt an earlier review?