A diabetic ulcer is a sore or wound that develops on the skin, often on the feet, due to complications from diabetes. High blood sugar levels can damage nerves and blood vessels, reducing sensation and blood flow, which makes it difficult for wounds to heal. These ulcers can become infected if not treated promptly, leading to more serious health issues. Proper foot care, regular check-ups, and managing blood sugar levels are essential for preventing diabetic ulcers in individuals with diabetes.