Leg sores that do not heal properly may indicate an underlying condition, such as diabetes or swelling in the legs, notes Cleveland Clinic. Sores that heal but keep returning can be a sign of skin cancer, according to the American Academy of Dermatology.
There can be many reasons that sores do not heal, according to Frederick Memorial Hospital. Infection may interfere with the healing process. Autoimmune disorders, such as lupus and rheumatoid arthritis, may also affect healing. Malnutrition or certain treatments, such as cancer treatments, can be underlying causes. Radiation injuries also do not heal normally, and sometimes radiation injuries can take months or years to appear.
Most leg ulcers that do not heal fall into one of three categories, according to Cleveland Clinic. Diabetes is one of the most common. Diabetic people often lose feeling in their legs, so it is hard for them to notice wounds. They also have poor blood circulation and a weakened immune system.
Venous leg ulcers are another common category, notes Cleveland Clinic. These often occur because the legs become so swollen that the excess fluid leaks out through ulcers. The other common category is pressure sores, which primarily affect people with limited mobility. These can develop in a fairly short time and can be prevented by helping the person move and using special equipment to relieve the pressure.