What Stress Is and Why It Matters

This lesson defines stress as the body and brain’s response to challenge, demand, or threat. It explains why stress is not always harmful, how it becomes a problem when it is too intense, too frequent, or too prolonged, and why understanding stress matters for health, performance, and decision-making.

You will learn the difference between stressors and stress responses, the role of perception in shaping stress, and the basic idea of the body’s alarm system. Later lessons will go deeper into the brain, physiology, and practical regulation strategies.