Why can medications sometimes safely reduce pain or fever?

In the context of Darwinian medicine, symptoms like pain and fever are often protective responses shaped by natural selection to defend the body against threats. While these responses are useful, they frequently trigger "false alarms" due to the smoke-detector principle.1

Much like a sensitive smoke detector that sounds an alarm when you make toast, the body’s defense mechanisms are calibrated to prioritize survival by ensuring we are alerted to potential dangers, even if it means experiencing unnecessary discomfort. Because the cost of failing to express a defense when it is truly needed is far higher than the cost of an occasional false alarm, natural selection has favored sensitive thresholds for these responses.1

Consequently, medications can often safely block these symptoms because the body’s defensive response is frequently excessive or unnecessary for the specific situation. For example, while fever helps the immune system fight infection, low-grade fevers may be safely left untreated, whereas higher fevers can be managed with medication when the defensive benefit is outweighed by the physical stress on the body.12