Which of the following is a sign of a pressure ulcer?

A darkened area after sustained pressure is a clear indicator of a pressure ulcer, also known as a bed sore or decubitus ulcer. Pressure ulcers occur when there is prolonged pressure on the skin that reduces blood flow to the area, leading to tissue damage. Typically, the affected skin may initially appear red, and if pressure is not relieved, it can darken, indicating more serious damage beneath the skin's surface. This discoloration is an important warning sign for caregivers to take action to prevent further injury.

The other options presented relate to factors that are not characteristic of pressure ulcers. Pain during movement may be associated with many conditions but does not specifically indicate pressure ulcer formation. Increased appetite and frequent urination are unrelated symptoms that do not connect to the risk or presence of pressure ulcers. Understanding these differences helps caregivers identify and address risk factors for skin integrity effectively.