Emotions are reactions that we all experience: joy, sadness, fear, anger ... They are known to all of us but they are not without complexity. Although we have all felt anxiety or nervousness, not all of us are aware that a mismanagement of these emotions can lead to a blockage or even illness. These are some of the easily identifiable situations and reactions that commonly occur in humans: Fear of losing your life or threat of a negative result. We react by fighting, fleeing, maintaining the alert situation or paralyzing ourselves. Confrontation of interests are our fellow men. We react with anger or anger. Loss of a loved one. We react sadly and empathize with the people who support us. Celebrating a success or infatuation. We reacted with exaltation. Effort in the face of a challenge. We react with satisfaction and joy. Before people who need our help. We react quickly and altruistically even at the risk of our safety. In all cases, these reactions help us to better cope with these situations. To explain more deeply the changes we experience, we are going to focus on the fear that, for example, we feel when faced with a dangerous situation in which our own lives may be at stake. At a cognitive level, that is, as regards our ability to understand, judge, memorize and reason, fear can make us lose the ability to control our behavior, causing us to react in a similar way to other less evolved species such as reptiles. That is, we will react by trying to decide if we have a better chance of surviving by fighting, fleeing or being paralyzed. This way of reacting, this "program", resides in the amygdala, in the deepest part of our brain. In this "emotional" body we do not have conscience or decision-making capacity and, in addition, the events that we have experienced and the sensations that we have perceived are recorded in it, which makes us not forget what has happened to us and try to avoid it in the future . Regarding the physiological level and depending on the behavior that we are going to develop in the face of the situation, a series of responses will be activated from different systems: muscle tension, blood pressure, respiratory rate, peripheral temperature, dry mouth, etc. which will prepare us differently according to the answer. At a subjective level, that is, totally depending on the individual, we will experience a series of physical, intense, unpleasant and uncontrolled sensations that together with cognitive changes and some thoughts about the danger and its consequences will make us have a unique and indelible experience of terror. We have already analyzed each of the three responses that occur. The sum of all of them is what will cause our behavior, whether it be fight, flight or paralysis, in the best conditions to save life and try not to see ourselves in a similar situation of danger again. On the other hand, there are emotional reactions that occur in situations that we have not experienced yet, that is, when we anticipate or imagine them. A clear example is what we feel when we see a scene in a movie, read a text or remember or think of an event. The hedonic tone, that is, the pleasure we experience or the pleasant or unpleasant sensation are "the spice of life." It is essential for memory, for decision-making, for our judgments and reasoning, for our behavior, our social relationships and our well-being since: - Emotional experiences are the most valued. As a curiosity, there are more than 15,000 words in English to define emotional states. - The memories we keep are mostly emotional. - We need emotional tension to decide. - We decide many times emotionally. - Emotions prepare us, motivate us and guide us. There are another series of terms and concepts closely related to this topic, such as...