Which term best describes a severe but short-term medical condition?

The term that best describes a severe but short-term medical condition is "acute condition." Acute conditions typically manifest abruptly and can be severe in nature, presenting a sudden onset of symptoms. These conditions usually require immediate medical attention or intervention but are generally expected to resolve within a short time frame, contrasting with chronic conditions, which persist over a longer duration and may require ongoing management.

In this context, the other terms do not apply as fittingly. A chronic condition refers to a long-term health issue that can last for months or even a lifetime. A residual condition signifies any lasting effects following a medical event or illness, while a preventive condition does not pertain to a specific health issue but rather involves measures taken to prevent diseases or complications from occurring. Therefore, an acute condition accurately captures the essence of being severe and short-term.