Stress is the body's response to a challenge or demand. Everyone experiences stress, which can be triggered by a range of events, from small daily hassles to major changes like a job loss. The stress response includes physical components such as an elevated heart rate and blood pressure, thoughts and personal beliefs about the stressful event, and emotions, including fear and anger. Although we often think of it as being negative, stress can also come from positive changes in your life.

Stress serves an important purpose—it enables us to respond quickly to threats and avoid danger. However, lengthy exposure to stress may lead to mental health difficulties (for example, anxiety and depression) or increased physical health problems. A large body of research suggests that increased stress levels interfere with your ability to deal with physical illness. While no one can avoid all stress, you can work to handle it in healthy ways that increase your potential to recover.