1. Definition

Concepts (psychological crisis and stress) involve or require a change because collide forces of different levels, which in turn are under the influence of regulatory mechanisms of biophysical and psychological type whose function is to achieve personal balance.

The stress response is not bad in itself, but to the contrary, facilitates more resources to deal with situations that pose exceptional. But since an extraordinary amount of resources are activated, it is an important wear on the body. If this is episodic there will be no problem because the body has the capacity to recover between each stress response. But if these stress responses are repeated with some frequency, intensity or duration, perhaps the body can not recover and the emergence of problems known to occur as psychophysiological disorders or disorders associated with stress. 
2. Types of stressors
a) Psychosocial: These are situations or stimuli that become stressors by cognitive interpretation or meaning that the person assigned, that is interpreted as threatening for the person. 
b) biogenic: are stimuli or situations that become stressors for their ability to produce certain biochemical or electrical changes immediately trigger the stress response, regardless of cognitive interpretation given to this situation.