Fatigue is the gradual weakening of a material, component, or system after repeated stress over time. Each load cycle may be small, but the accumulated damage can create cracks, loosen connections, distort parts, or reduce performance until failure occurs. In engineering, this is why builders track vibration, heat, bending, and repeated start-stop cycles instead of looking only at peak force.
In cyber security, fatigue matters because many attacks and defenses depend on long-running systems and human operators. Hardware fatigue can affect cables, fans, solder joints, and storage devices that must endure constant use, making reliability and maintenance part of security. On the human side, alert fatigue and push-notification fatigue can make analysts or users overlook real warnings, which attackers may exploit with repeated login prompts or noisy distractions. Good defenses reduce unnecessary stress, rotate worn components, and test for early signs of degradation before weakness becomes compromise.