An arterial ulcer is a type of wound that occurs due to poor blood circulation, often caused by conditions like peripheral artery disease. These ulcers typically develop on the feet, toes, or lower legs and are characterized by a round shape, a pale base, and a well-defined border. They can be painful and may take a long time to heal due to insufficient blood flow. The primary cause of arterial ulcers is reduced oxygen and nutrient supply to the skin and tissues. Risk factors include smoking, diabetes, and high blood pressure. Treatment often involves improving blood circulation, managing underlying conditions, and keeping the ulcer clean to prevent infection.