Stress is a complex physiological and psychological response that occurs when an individual perceives a situation as challenging, threatening, or beyond their ability to cope. In critical care nursing, understanding the factors affecting an individual’s response to stress is essential because critically ill patients often experience severe physical and emotional stress due to illness, invasive procedures, pain, and uncertainty about outcomes. The response to stress varies greatly among individuals depending on multiple factors. Age is an important factor influencing stress response. Infants, children, adults, and older adults may react differently to stressful situations. Children may express stress through fear, crying, or behavioral changes, whereas older adults may experience increased anxiety, confusion, or difficulty adapting to stressful conditions. Personality characteristics significantly affect how a person responds to stress. Individuals with a positive attitude, emotional stability, and effective coping skills are usually able to manage stress better. In contrast, people with low self-confidence, anxiety-prone personalities, or negative thinking patterns may experience greater stress responses. Previous experiences and learning influence an individual’s reaction to stressful events. A person who has successfully managed similar stressful situations in the past