What type of injury is characterized by sudden pain and swelling in a joint?

The correct answer is a sprain, as this type of injury specifically involves the ligaments that connect bones at a joint. When a sprain occurs, either through a sudden twist, fall, or impact, these ligaments can become overstretched or torn, leading to immediate pain, swelling, and often bruising around the affected joint. The sudden onset of these symptoms is a hallmark characteristic of a sprain.

In contrast, a fracture refers to a break in the bone, which may also cause immediate pain and swelling, but is primarily identified by specific symptoms related to the bone structure, such as deformity or inability to move the affected limb. A strain involves damage to muscles or tendons rather than ligaments, typically resulting from overuse or overstretching, and may not produce the sudden swelling and joint-specific pain seen in sprains. A dislocation occurs when bones at a joint are displaced from their normal position, which can also result in immediate pain and swelling, but it is marked by visible deformity and loss of joint function, distinguishing it from the specific ligament damage associated with sprains.