Stress can be defined as mental tension caused by difficult situations and is the body's reaction to events. There are different types of stress including general stress that resolves quickly, cumulative stress that builds up over time, and acute or post-traumatic stress from critical incidents or trauma. Long-term stress can lead to physical symptoms like insomnia, appetite changes, and frequent illness. Healthy ways to manage stress include eating a nutritious diet, getting sufficient rest and exercise, relaxing activities, and seeking social support.