What term is used to describe a rapid onset injury or condition?

The term used to describe a rapid onset injury or condition is "acute." This refers to situations that arise suddenly and are usually severe in nature. Acute injuries are often associated with a specific event, such as a fall, a sprain, or a fracture, where symptoms appear immediately and require prompt medical attention. For example, if an athlete twists their ankle during a game and experiences immediate pain and swelling, that injury would be classified as acute.

In contrast, chronic injuries develop over a longer period, often due to repetitive stress or overuse. Subacute injuries fall between acute and chronic, indicating a phase where the condition is neither fresh nor fully resolved. The term "transient" generally refers to symptoms that are temporary or brief, rather than to the onset context of injuries. Thus, acute is the most accurate term to describe injuries or conditions that manifest rapidly and demand immediate attention.