A threatened limb is a situation where a person's limb (arm, leg, hand, or foot) is in danger of being injured or amputated due to a medical condition, injury, or infection. This can be caused by various factors such as diabetes, poor circulation, trauma, or nerve damage. In such cases, immediate medical attention and treatment are required to prevent further damage and preserve the limb. Failure to address a threatened limb can lead to severe pain, disability, and even death in extreme cases.