Warning

A warning is a notice or indication that a person may be exposed to danger, loss, or an adverse outcome, and is intended to enable precautionary action. Warnings can be explicit or implicit and may be conveyed through speech, writing, symbols, alarms, or other signals. They serve to reduce risk by increasing awareness and prompting appropriate responses.

Warnings are used in many settings. Safety warnings appear on products, in workplaces, and at construction sites to alert workers and users to hazards. Weather warnings tell the public about imminent storms, floods, or extreme temperatures. Traffic and travel warnings inform drivers and travelers of conditions that may affect safety or travel time. Medical warnings communicate potential side effects or interactions of medicines. In software and information systems, warnings prompt users about potential errors, data loss, or deprecated features.

Common mechanisms for delivering warnings include signs, labels, audible alarms, notifications, and advisories. The effectiveness of a warning depends on clarity, credibility, urgency, and relevance to the audience. Warnings can fail due to ambiguity, message overload, cultural differences, or warning fatigue when too many alerts are issued. Proper design often pairs the warning with concrete instructions on what action to take and how to respond.

In law and policy, warnings may accompany obligations or restrictions, and failure to heed them can have legal consequences. The term derives from historical roots related to cautioning or warding off danger, reflecting the purpose of anticipatory guidance to prevent harm.