A stressor is any event, condition, or stimulus that triggers stress and causes a physical or psychological response in the body. Stressors can be categorized into three main types: catastrophes; significant life changes; and daily hassles, including social stress. Each can be detrimental to physical and mental well-being.

Catastrophes
Catastrophes refer to large-scale, unpredictable events that create overwhelming stress and a sense of threat. Examples include natural disasters like earthquakes, tornadoes, and hurricanes, as well as human-made disasters such as wars. These events not only cause immediate physical harm but also result in long-lasting emotional and psychological damage. For individuals displaced by catastrophes, such as those forced to emigrate, the stress is compounded by the challenges of adjusting to a new cultural environment, which may involve language barriers, climate adaptation, and social integration issues.

Significant Life Changes
Major life transitions also contribute significantly to stress. Events such as marriage, divorce, job loss, or the death of a loved one demand substantial emotional adjustment. Even positive changes can be sources of stress; graduating or moving to a new city can be sources of stress, as they often require new routines, responsibilities, and adaptations. Coping with these changes plays a central role in the stress experience, as they disrupt an individual's normal state of equilibrium.

Daily Hassles and Social Stress
While major events contribute to long-term stress, daily hassles often have a more immediate impact. Minor frustrations — traffic jams, social media overload, or interpersonal conflicts — may seem trivial but can accumulate to affect overall health. Daily stressors are closely linked to short-term ailments such as headaches, colds, and muscle tension, reflecting their direct impact on well-being.

Likewise, social stress, arising from frequent social interactions and constant social media notifications, can amplify daily frustrations and negatively impact overall well-being. This type of stress is linked to the pressure to respond, keep up with information, and manage relationships online, which can lead to feelings of anxiety, overwhelm, and mental fatigue. Over time, this continuous exposure to social demands can contribute to stress-related issues like burnout, sleep problems, and lower emotional resilience.