Stress is a state of mental or physical tension caused by factors that disrupt equilibrium. It has been linked to various health problems. Life changes, both major and minor, can be stressful. Holmes and Rahe developed a scale to measure the impact of life changes, finding that even small changes can have significant effects. Characteristics of stressors like significance, duration, cumulative effect, and approaching deadlines impact how stressful a person perceives a situation to be. Their perception is also influenced by their self-concept and emotional needs.