Stress can be defined as the body's reaction to changes or demands placed on it. There are three stages of stress: alarm, resistance, and exhaustion. In the alarm stage the body prepares for "fight or flight." In the resistance stage the body works hard to cope with stress but becomes exhausted. In the exhaustion stage the stress persists and the person becomes drained physically, psychologically, and emotionally. Stress is caused by both external stimuli and an individual's response. Common personal causes of stress include finances, health, relationships, and death. Prolonged stress can negatively impact physical and mental health.